On plane travel
blogs.gnome.org
blogs.gnome.org
http://matrix.itasoftware.com - especially once you learn the advanced QPX language, e.g.:
SFO,LAX CX,AA,KE F HKG,ICN,NRT ~CZ+ KMG
Search for flights from LAX or SFO, on Cathay Pacific, American, or Korean Air, a single flight to stopover cities Hong Kong, Seoul, or Tokyo, then any number of flights except on China Southern to Kunming, China (where I happen to live).They're also the source of inspiration for Hipmunk's Time Bar interface.
The one downside: you can't book directly through them. But once you know your exact itinerary you can go book somewhere else. Sometimes you'll have to call to get the fare code/construction that Matrix recommends, as it won't always come up in an airline website or kayak search.
http://kvstool.com/ (Subscription required, windows/WINE) Search all kinds of fare, routing, timetable, award info. Uses the Sabre, Amadeus, and Worldspan (the 3 major info brokers). Has a pretty decent mobile website that has saved my ass more than once (I can see that there's open seats in business on a particular flight, etc).
And down the rabbit hole: http://flyertalk.com/
Lots of people also like http://expertflyer.com/ (subscription required) as a web-based alternative to KVSTool, but I find its search engine too restrictive and the results more difficult to quickly parse.
It also was great the one time I was 4 segments away from requalifying for platinum on AA and needed to make it up before the end of the year. That routing language is good when you need to stuff extra segments into a trip and have them be on a specific airline.
Turned out the cheapest route was to have me go to Omaha (by way of Chicago) where I met a friend for lunch in the airport cafeteria and then hopped right back on a plane home.
Unfortunately, I have to agree here, which is unfortunate for sites like Hipmunk and Kayak.
I once booked through Expedia (years ago) a return flight from the UK to Australia and accidentally picked the wrong airport. I lived not far from Heathrow but I picked a departure from Gatwick and return to Heathrow. I rang up the airline (Emirates) and they said they could change it if it was booked through them and Expedia were no help.
Nowadays American Airlines has all my details so booking flights through their website is easy.
Hipmunk provides a great interface and I feel bad for not booking through it but I've been burnt on this a number of times so just won't do it anymore.
Plus there are other advantages like seat selection through the airline's website.
Perhaps the business model for online travel booking needs to evolve from the current commission model to an affiliate model like Amazon. If, say, Hipmunk directs you to aa.com they get a commission on purchases made by you on aa.com for the next 24 hours or whatever.
The biggest tip I would add on: just because an airport is named for a city, doesn't mean it is close. For example budget airlines in Europe often pick really shit airports, such as London Stansted, or there's an Oslo airport that is ~90 minutes away from Oslo. Even for decent airports, depending on your final destination, there could be a big upside/downside chosing between London Heathrow or London Gatwick... New York JFK or Newark..
For instance, in Philadelphia, the airport security is outside of the inner walkway which connects terminals D & E. E was the international terminal, so there was always way less traffic going in/out of the gate. Sometimes D would have a security line backed up to the curb. Simply walk over to terminal E and bypass the entire line.
Similarly, in LaGuardia, there are two taxi lines outside the American terminal. One is all the way at the end, hidden from sight. Everyone not familiar with the airport just lines up at the main one and if you walk around the edge of the terminal you can hop in a taxi right away.
Anyone seriously optimizing their travel, though, will most likely be a loyalty member of some airline alliance and the goal is to maximize your upgrades (free or otherwise) to always fly business/first.
For example, AA has a "challenge" where you can automatically earn Platinum status if you earn 10,000 points in 90 days. This isn't terribly difficult if you're flying to an international conference. You quite literally call a 1-800 number and say "I want to take the challenge." Platinum gives you automatic domestic business class upgrades when available!
In most cases roundtrip is way cheaper, even if you only require a oneway flight. The cheapest roundtrip from Vienna to San Francisco is something like 700 EUR, with oneway it costs around twice as much for half the flights (1400 EUR).
One notable exception for flights between US and Europe is Air Berlin, where oneway costs only half of roundtrip. But they only fly on certain days under the week and may therefore not show up when you search for a site.
Next best option is to just book roundtrip and just let the return flight expire. Warning: Most airlines invalidate all the other flights after you've missed on of them. So make sure to only let the last flight(s) expire.
And the most important rule at the end: Never ever (even if it's free) fly Air France or over CGD airport. The experiences I had there were (multiple times) so awfully bad that one wouldn't believe them if I told then.
To avoid: Ryanair. Seriously, even if it's cheap it is not worth it. Also, the one time I flew with Alitalia I got the worst headache I've gotten flying.
Also, http://skyscanner.net/ has not been mentioned yet. From the article, Amadeus seems to do something similar, but I've only used Skyscanner so far and have been quite happy with the results.