Denshi Jisho is now available for Japanese mobile phones. It works the same way as the main site, with only the kanji by radical search missing, and I hope to add that at a later date.
Just go to jisho.org with your Japanese mobile phone and it should automatically take you to the keitai version.
You can also use k.jisho.org to access it from any device.
Thanks to the members of the Tokyo Linux Users Group mailing list for testing and comments!
Enjoy!