Simply saying you are working on opensource programming will show that you code as a hobby. I can't agree with this statement. There are simply too many people out there who say "I'm working on building my own OS kernel written in Perl" or something like that. Just look on SourceForge for projects that were started years ago but have yet to release any files and likely never will (I'm guilty of creating a few of them) (yes, I know they're starting to clean out stale projects).

Not wishing to put words in his mouth, but when I read that line I thought the whole "working on an opensource program .. as a hobby" meant more along the lines of you honestly enjoy coding, enough to do so in your outside time as well. It seems to me that an employer would prefer to employ someone who likes what he does, not so?

But of course you are absolutely right about the whole starting and not finishing thing, and there do seem to be large numbers of programs like that.