Which start-up inspired you most in 2010?

Groupon. I consulted briefly for them when they were ThePoint.com and I thought their original idea for ThePoint was a really bad one and they were going nowhere. Within a few months they had completely changed their business model and were profitable. Then they became massively profitable and Google wanted to buy them for $4 billion.

What I love about Groupon is that in the world of Google they've proven there is still a huge amount of revenue and profit available online.

They are also showing that revenue still counts for a hell of a lot and that pure growth without profit is not the only strategy and may even be a bad strategy.

I also love that they fly in the face of Google's attitude that software should do everything and the main role of employees is to write software. Groupon is a people company in the sense that people in their business deal directly with their customers (the businesses they market).

Groupon are also targeting a hugely unexplored space which is small to medium local businesses that target local customers. They're doing it with boots on the ground (or at least via a person to person phone call) in each city the launch in. So far "local" has been a cluster of servers in a data center and a group of developers. It feels like Groupon is doing local the way it should be done.

I also love that the Google/Groupon deal didn't work out because I think Google's culture and approach would have killed a wonderful business that we all continue to learn from.

Although its been overexposed in the media, the reality for me is Facebook. Not since Google have we seen a company expand to that magnitude of usage within the wider population.

Facebook was probably the first truly bubble 1.0 company to reach that milestone, and will pave the way for many other companies to do the same.

Foursquare (http://foursquare.com/).

Foursquare's ascension into the mainstream has been incredibly fast & impressive, especially given that on the surface there was little differentiation among all the competing LBS check-in services a year ago.

I think 4SQ is a good case study in the importance of the execution over the idea (a commonly harped on subject in these parts).

4SQ's success also helps to validate NYC as having some distinct advantages for certain types of social media plays.

It's still fresh, but Word Lens blew me and everyone else away this week.

Kickstarter - I can post a project, and potentially get thousands to hundreds of thousands of dollars...without loosing equity?! Game changer.

Wikileaks, since a tiny group of people with limited resources has had such a big impact on politics, media, diplomacy, and war. I don't like or agree with some of what they have done, but they have undeniably changed the world.

Quora, for developing an amazing realtime UI and a great core of startup industry content and community.

Groupon, for breakout mass market commercial success from basically obscurity.

Guestlist (guestlistapp.com) partially because I'm privy to some of their internal numbers and partially because they are some of the nicest guys in the whole Toronto tech scene.

I don't know if they are a startup or an offshoot of someone else's already existing technology, but the group behind WorldLens (QuestVisual) have my votes. Yes maybe I'm saying that in light of this week's release being on my mind, but I think they have some wicked cool technology. Shockingly wicked if I say so myself. Hipmunk would be my vote for second.

Groupon, because they found a simple multi-billion dollar business hiding in plain sight.

HipMunk. They demonstrated that design & UI really matters.

Dropbox, because it solves a real problem my family has.

My own. Doubled the revenue and will do it again next year.

Hunch (http://www.hunch.com) for tackling a very hard problem (recommendations) and being pretty good at it.

Quora (http://www.quora.com) has assembled a community of brilliant people who inspire me daily. Q&A done right - hope it stays this good!

Quora or Groupon.

Quora because it provides an extremely high-quality Q&A community.

Groupon simply because of the crazy growth and insane amount of revenue/profit they generated.

Heroku, because their comparatively monstrous exit fully validated the YC model.

Groupon refuses to inspire me. I am amazed at their growth, their adapting from ThePoint and their billion dollar valuations but I just don't see it as a viable business model Case in point, the two times I have bought such deals it was from Living Social even though I track Groupon every day.

So back to the original question, what inspires me is not one particular start up but all the open source contributions that are enabling these start ups including mine. It just wouldn't be possible for someone like me (full-time Windows dev) to bring my ideas to reality if not for the Ruby on Rails framework, jquery and the countless number of plugins.

The branding behind Foursquare has been amazing (http://foursquare.com/)

Not to mention the power they have with mobile apps on all major OS'

Y Combinator probably does not count as a startup. But I'd still have to say YC has been the most inspiring company for me in 2010. Seeing PG talk at startup school about why right now is the best time to do a startup had a large impact on me. I'd argue that currently having the YC stamp of approval for a web/tech startup has more value and credibility than any other single incubator/funder out there. And its probably one of the best things that can happen for an early stage tech startup.

Sencha (http://www.sencha.com/) is doing very well and innovating in a cut throat industry.

Rovio Mobile: Angry Birds.

For popularizing phone gaming. Having franchise potential in other platforms and even past games.

When it comes to inspiration, it's hard for me to name any startup other than YCombinator, even in 2010.

I can't think of a specific start-up that has inspired me.

What has inspired me is the explosion in the sheer number of high quality apps/gadgets/tools/etc. that are actually innovative.

It was inspiring to see Foursquare make it to the mainstream.

Also, Heroku. But I'm unsure about the future after the acquisition. Hopefully they'll stick around and continue to rock!

Whapee (http://whapee.com) as they bring back the old-school account free internet and keep privacy on location based services.

Of course Groupon is amazing and Word Lens is jaw-dropiing but I really am fond of intersect.com because it is such a good idea.

probably groupon, they had huge growth in 2010

AirBnB's story was pretty inspiring.

messagehop.com is a pretty awesome idea.

MineCraft

feefighters. Real business model, solves a real problem.

Fee