m.paypal.com is a mobile site. i use it all the time...
also, if you find the thread about 15 free shortcuts, the author made a shortcut i requested, that had the paypal logo .png and directed to m.paypal.com
i'll go look for the thread.. Free: Custom Web Shortcuts
Only think is it is a stripped down version, no transactions, but you can view balances, and send payments as well.