I remember using a TI calculator in school to do advanced math. It was a great little calculator but the outside made me feel like a nerd because it was so blah. Those were the early days and things have changed a lot since then.
Now you or your kids can spruce up those calculators with a snappy pre-made cover or you can create your own design. Oh, man! I wish we had these when I was in school. Anyway, you can get your free cover here.