One of the biggest problems nowadays is to being able to encode or decode to/from base64 . Jokes apart, if you need to quickly check a base64 string, try this encoder or this decoder ( mind the note before using them ).
Pretty nice application for Facebook - It enables you to see statistics on keywords on the public walls. Give a look to it here: http://www.facebook.com/lexicon/ and try for example: " brawn, ferrari " or " iphone, ipod ".