I've been investing in my 401k since I was first able to when I was 21. I started with the minimum 4% to get the company match. It seemed to take for ever to get anywhere. About 2 years ago I upped it to 6%.
I got my statement today and my balance is over $19,000. Woohoo! It seems like it took for ever to get past the $10,000 mark but now its been making some nice jumps each time I get a statement.