Advice needed: what CRM for cold calls and follow-ups?

Hi. I'm looking for a fairly simple CRM to track (mainly outbound) phone calls. The few requirements we have are the following:

• easy to add new leads using a few fields (name, number, perhaps also address)
• ability to pick leads from a queue or assign leads to an agent
• ability to take notes during a call
• ability to assign some kind of follow-up, e.g. "call back in 2 days", "send info by email", "send info by snail mail", etc.
• if a lead has to be called back, he should show up again in the queue, obviously

Any recommendations?