You may recognize the LA River Trails from the classic truck chase scene from Terminator 2: Judgment Day (you know you want to watch it again now, so HERE IT IS).
There is a paved bike trail now that runs along the river, so I rode it the other day. Not the most exciting, but it's flat and if you're out there without too many other people you can open it up. Coming from the Midwest, to be able to ride surrounded by mountains and palm trees cannot be beat (especially when I'm seeing photos of Jeff with shoe covers on in MPLS!).
For you birdwatchers: