My list is mostly trips and adventures that I want to do. Sometimes I'll pick up an idea when I talk to friends. For example, I was comparing hiking trip notes with a friend and he mentioned how great his Denali trip was. Well that's definitely on my list of future trips now.

I also get many ideas from this forum and sites like it. Right now I'm reading the trip report on crazyguyonabike where a guy rode his bike from Anchorage to Miami. Wow! I'd love to do that.