Cryptojam is a tiny web site where you can solve cryptograms. The database contains over 100 puzzles of varying lengths and difficulties. The initial download is about 12.5 KB uncompressed (for the longest puzzle) but less than 4 KB when gzipped. To see the longest puzzle, use ID "thoE" (add "?p=thoE" to the end of the URL). Not real big on cryptograms? "PMnS" or "jcpO" should be fairly easy.
View the source of this project on GitHub: https://github.com/Triskaideka/cryptojam