Delta has distributed 50 tablet PCs to pilots for review and comment on their feasability as an electronic flight book. A PDF Reader, while very useful, is not what the Senior VP of flight ops is looking for...he wants something more integrated and easy to use. We'll probably have a decision by this fall on what we'll use.
The selling point for the company is the weight savings of two flight kits distributed over 700 aircraft and thousands of flights daily in an effort to save every bit of fuel.
I own an IPad and am a big fan. I've got all my Airbus pubs and applicable jepps for any trip I fly. Also have the Skycharts app for IPad that uses all the NACO charts, TPCs and area charts for anywhere in CONUS. I don't use it on the flight deck, but use it for review outside the flight deck. I can also check Wx and NOTAMs on my IPad.