Basecamp an 37 signals have a website (http://www.basecamphq.com/?ref=tadapub) for project management. I have been using the site for my current production of Pirates of Penzance. I am currently using the 1st level of the paid service as I needed to be able to share files. The primary reason for me to try this was that my ATD and I (the TD) have had very different schedules over the production period for this show, and we needed a way to share files and keep track of where the show was in while in process.
The good stuff:
-it is very simple to use and set up
-others can see and alter the site as needed in the project (like mark off done items)
-the free site is good, for files, the upgrade is still economical
-it has really worked well to keep all of the members of my team on the same page
-the file exchange is nice. It would be even better if you could have a free account with a file exchange. 3 projects at a time aren't of use to me, but the files are important
The not-so-good stuff
-lack of flexibility - for instance, some of the terminology is different that what we normally use, and you can't alter it. Also, more formatting options would be nice.
-printing options could be better, for instance allowing you to print only what needs to be done on a list
-archiving a finished project to an offline document would be great. the current option is to archive it on the site. If you are a paying customer you can downgrade to a free account to maintain the archived projects
-web address universal through all projects. I would have used a different address had I known this to start with
Overall a good system. I would use it again in a similar situation. If you have a situation where members of the team work on the project at different points in the process this may work well for you also. Plus, you can try it out for free and then upgrade it if you need the files sharing services later.