Getting back to the point, I've drawn on Matt Gemmell's http://mattgemmell.com code on more than one occasion. He has some really great stuff on his site that you can borrow, modify, worship....whatever.
When you find a decent modification and add an enhancement to someone's existing open source code, then it's your responsibility to share so that others can learn (or pilfer) from your stuff - just as you have done. If you don't then you've failed all the other code kiddies that follow you and you can potentially cause irreparable damage to the space time continuum (OK, maybe I'm overstating it somewhat).
The Point...
How do you do this though? How do you contribute your mediocre code to that awesome class some guy posted on his blog?
Well there's a simple solution that might seem antiquated in a time of Web 2.0 and SVN, but it actually works. You place a light bulb above your head and email the guy your code. If they like it enough they might even update their code accordingly. Crazy.
How did I discover this incredible revelation - I emailed Matt Gemmell with my code modifications to one of his classes and he updated his and reposted it. Awesome. See here: http://mattgemmell.com/2008/05/12/imagecrop-updated
for results.