yahoo groups lets you set up a discussion thread much like this one very easily. Plus you can opt to make it public or by invitation only. And yahoo groups has the capability of working either by email or by direct web access. And it's free.

main site:
http://groups.yahoo.com/

there are yahoo groups already for quite a few special interests, including

Band in a box...
http://tech.groups.yahoo.com/group/Band-in-a-Box/

sonar/cakewalk
http://launch.groups.yahoo.com/group/cakewalkproaudio/

tc helicon
http://launch.groups.yahoo.com/group/tchelicon/

fruity loops/flstudio
http://tech.groups.yahoo.com/group/fruityloopsclub/



there may already be one for contract nursing professionals. Just go to the main site (1st link I posted) and search for various keywords to see what comes up.