built-in unrar app in snow leopard?!?

hi all, i recently reinstalled my os and now i want to unrar a file i cant seem to be able to use the built-in option in snow leopard or find it again for that matter, goolging it is no good, i keep getting advice to try downloading apps which i dont want to do!! i thought the option i'm thinking about was in utilities but nothing is ringing a bell!

any help would be great

*confused!!