Sweeeeet!
The more guinea pigs I see on here and at our local kids' zoo, the more I'm thinking that they would be a great first pet for minimac when he's old enough to share/take responsibility. I always had hamsters so I'm a bit torn...
I'm also hoping minimac would like a couple of rats when he's older. They're great too.
This is all dependent on how long our cats last out, of course!