I use Kitty wireless and Pageplus. I really like it.
We just get $10 loaded on each of our phones every 4 mos....so it's a killer deal including data (mind you it's 0.10 a minute and 0.10 a Mb, so only for low usage people). DH SAH, so he has the house phone all day (on Obitalk and Anveo for $3 a mo)and I use my work phone or if we're somewhere with wifi (like home and work) we IM through Googlechat, so we don't use much and this meets our needs.
I don't mind the 0.75 reload fee of Kitty because it amounts to less that $5 a year for DH and me and with it Kitty reloads our minutes before they expire and/or when they get below $2, so we never have to think about running out or keeping track.
I'll track how much we spend and if we ever go over, but based on past usage, I think our plans for 2 smart phones will cost us less than $100 a year. Again, this is very light usage, but all the bells and whistles available for the few times a month we could use it, not having to add minutes ourselves or monitor anything for usual usage, and the ability to easily choose to add more minutes (for less per minute than our usual lading) easily if we think we'll have a rare heavy-use month coming up (eg, are traveling). Oh, and obviously no contract so we can adjust easily if our needs ever change.