ZohoCRM is free for a single user, and you can upgrade later. It's not pretty but it works quite well for me. For Skype 'integration', I use the Skype Firefox plugin so I can click phone numbers to call people. It's not really 'integration' since you still need to manually enter a 'phone call' for your contact but you can do that while the phone is ringing, it works well for me.

I haven't found any other (free) CRM systems that worked for me. I tried vTiger installed locally but it's not very stable nor moving fast - not something I'd want to base business on.