www.ownskin.com
It doesnt formally support the E61/62 but I've made many themes under the N73/N93 and it works out well if you stay away from photos and pictures with logos. Works great if you take a generic desktop picture as it stretches it.
http://www.howardforums.com/showthread.php?t=1043692
bad example I made in a matter of seconds but it shows how easy it is.