For instance - I needed to modify one of those modules that takes care of config files. I'm not anymore sure which one it is (nor where it is on my computer - repository should help with organization) - it supports blocks (.ini style). And I needed a list of all the blocks in the config file - but that feature was missing. So I added it ...

I did send an email to the author, but without response ... guess he didn't wanted to bug with a guy that doesn't know to use diff and submit a patch :D