Are these good ideas for open source projects?

I'm looking at mythtv and open office as open source projects I might want to contribute to. Have any of you worked on these? How difficult is it to get involved and contribute work?

Thanks

I don't know about those projects in particular, but some developers are total jerks, i.e. the main developer of Audacious. The developers of VLC are probably nicer, but seem very bitter on the boards.

I'd just be cautious and offer patches...

Yes, I plan to be very cautious. Working with people can get tricky, so I'm keeping my options open. Fortunately, I will not depend whoever I work with for my paycheck!