I use a Ipaq PDA for this but you can use any form of PDA with software.
Below are some software web pages the 3rd one is all freeware and really good programs made to suit the PDA * Better hurry if you want to get the software i notice a statement on the site that he is closing it down very soon.
http://astro.isi.edu/pleiadatlas/ Palm OS
http://www.nomadelectronics.com/ Windows Mobile OS
http://www.interq.or.jp/taurus/roba/pocket/index.htm Windows Mobile OS
I used the PDA for the "push to" system on my dob with the full sized base setting circles and digital inclinometer. looking up the Alt/Az for the object on the PDA
Plenty of reasonable priced PDA`s on Ebay