Unless you need a "special" CRM feature, I think you can get by on using a generic tool that fits your workflow, and is simpler to get going with.
I'm building Notedock[0], it's really a general tool underneath all messaging on the homepage. I actually use it as a CRM, with a page for each contact (you can put all relevant details here, discussions, contact info, etc.)
If anyone's interested, send me an email and I can show how I get by with this "CRM".