Apptorney®: IP is a an iPhone app (works on iPad and iPod Touch too) our firm created last year. It contains links to the main USPTO and international pages for searching trademarks and patents.
I use it the app the time (biased opinion of course). When I think about a trademark while in line at the bank or on the subway or anywhere (yes, I am that much of a trademark geek) and want to know more about it and see if it is registered, I use Apptorney to get to the USPTO search page in 3 quick buttons, without having to remember or type any URLs. Then I search and if I find an interesting record, I pull up the USPTO TARR version of the record and click the “envelope” icon to email the TARR link to myself. Then when I return to my desk, the link is waiting for me!
What are your favorite mobile tools for I.P. lawyers?