How can I get a bigger gig size for my i-pod nano?(yes the first thin nano)

I would really like to find out how to put more memory on my 1 gig i-pod because I think it’s a great i-pod! If I can get a bigger gig size than I wont have to waste money on a new one, I mean why buy a new one when there’s going to be new, and better i-pods that are going to just keep coming out?