A few days ago, after reading Charlie's post about Twitter and mobile URLs, Filipe Boldo of esyURL emailed me and asked what I thought about having Mowser integrated into the esyURL url-shortening service. I responded and said that I thought it'd be a great idea and pointed him to some code examples on the wiki that might help.
Well, I'm not sure if the code helped, but a few days later and it's done! Cool! I just tried it out with the url to this blog, and got back an esyURL like this: http://www.esyurl.com/31d, and when clicking on it from a phone (or a spoofed header) you get a page prompt that asks you if you'd like to go to the original or view a mobilized version powered by Mowser. Very awesome!
So, if you want to send a shortened URL, and you're not sure if someone's going to access it via a phone, definitely send it via esyURL!