Looks like a few weeks ago someone released a Basecamp client for several mobile platforms, including my favorite, PalmOS.
I'm working on 2 short films, a documentary, and another documentary right now on top of my day job, and the busier I get, the more Basecamp reveals itself to be a lifesaver. This little palm app, Tracker, is ugly, seems to be written in Java, flaunts palm UI conventions and has a frankly bizarre setup procedure. It also seems to work, and right now that's where the bar is.
For anything I manage by myself, I still love you SHADOW, the best outliner anywhere...but the collaboration thing is so undeniable once you start seeing it in practice, and being locked out of basecamp by the Treo's low-end mobile browser is very frustrating. Tracker seems to work by using a server backend to grab info from Basecamp and then pass it along to the handheld; it has to re-sync a project from time to time, but it's all there - milestones, messages, comments, to-dos. Actually...alllll the to-dos are there, even completed lists, which is a bit annoying...clearly still a 1.0 product. Also, no writeboards, but it's understandable; that could be pretty tricky on a small screen.
Making Basecamp genuinely mobile is a huge step - I'd been considering picking up PalmOS development myself again to do this one - and so I am thrilled to have Tracker around. I assigned it a hot-key within 5 minutes.