give it to your cat. Cat found it first and if the cat found it, i bet there is more little mouse around the house. Let the cat do his job..free you of them critters.
I let it outside.. heres the pic (its a little big sorry) http://strathcl.com/upload/uploads//409361813fcf1b0b59eac4751d71778b.jpg
Oh he was cute for sure, sounds like you have a nest in your house, that could be a problem, in the mean time you can build a blog about the adventures of Little Mouse.
i'm guessin you don't wanna keep it as a pet, and well if you "misplace it", it'll either become a pest for you, or the cat will get it.... do you know anyone who keeps mice that'd possible want it?