You can pretty easily create your own profile plugins, actually. The biggest thing missing though is a picture field, which can be huge or no big deal, depending on whether you want avatars.
For info on how to create your own, check out the following articles. It's mainly a matter of copying the User - Profile plugin, making some naming modifications, and then changing an XML file with the fields you want. I've never done it, so I'm sure it's a little more involved than that.. but a lot less overkill than CB:
docs.joomla.org/Creating_a_profile_plugin
brian.teeman.net/joomla-1.6/enhanced-use...-t-use-a-hammer.html
Hope that helps, and good luck!
Alex