Be very careful when downloading programs and packed files. Not all users are nice people. Some put nasty stuff into zip/rar files that are bigger than 1 MB and look legit. A friend of mine got infected by such a file a few months back.

The file said it was some kind of poker ebook + some other things, but when he opened the zip file and clicked on this one pdf file, it was not really a pdf file but a nasty program that infected his PC with Look2Me spyware and browser highjacker and some other nasties. It wasn't easy to get rid of either.

He has been using Limewire for years and knows the common filesizes, autogenerated spam and such. He said that everything pointed to this file being legit prior to opening it.