You've lurked for the past few months? Have you read these:

http://news.ycombinator.com/item?id=1974726 - 6 days ago, 27 comments

http://news.ycombinator.com/item?id=1750877 - 71 days ago, 35 comments

http://news.ycombinator.com/item?id=1916801 - 25 days ago, 32 comments

http://news.ycombinator.com/item?id=1870456 - 38 days ago, 1 comment

http://news.ycombinator.com/item?id=1796372 - 57 days ago, entire blog post.

You're asking the same question that's been asked a dozen times. Have you read the previous replies?

Try reading these:

http://news.ycombinator.com/item?id=1996830

http://news.ycombinator.com/item?id=1994998

http://news.ycombinator.com/item?id=1360665

If you're serious about a startup then one thing you'll need is hard work, lots of time, and dedication. Start by showing some of those qualities. Read the above advice, find more, then summarise it properly. ON the way, ask yourself what you're finding annoying, awkward, tedious or painful.

There's your idea - solve that problem.