Unescape Converter
is a fantastic web tool for encrypting and decrypting links, esp email links to prevent bots from picking them up.
Text characters are replaced by hexadecimal escape sequences or vice versa.

Examples:
Unescape text: hello world ?
Simple escape text: hello%20world%20%3F
Complete escape text: %68%65%6C%6C%6F%20%77%6F%72%6C%64%20%3F