Hello Mrs M,
Have you heard of Ning? www.ning.com is basically a platform for creating your own social network. It can be implemented very professionally but most of the time it isn't. Below are two examples, I'll leave it up to you to decide if these are good or not.
http://crepig.ning.com/ - Commercial Real Estate Professional Investment Group
http://marketingcenter.ning.com/ - Marketing Center
The platform gives you all the usual 'social network gubbins' out of the box and it is cheap (free most of the time). I realise this is probably a million miles away from where you want this project to end up, but with social network the most important this is the users, getting your idea launched on here will give you the opertunity to start developing a user base while a better solution is developed?
Don't know if the helps,
MyCult