I'm currently a VZW customer waiting for my contract to end before porting all my numbers to Ting...but then I saw a news article for Zact. They have a similar phone plan like Ting, and they offer minutes, text, and MBs in more buckets. http://www.zact.com/plans
They both run on Sprint's network. ting has a much better selection of smartphones and better customer support, but Zact seems to be slightly cheaper. Also, it seems that Zact doesn't have a per device fee. If ting or Zact offered tablets as part of the plan, then that's the company I'd probably go with.
What do you guys think?