Its great in the IT field. Check out my thread in the iPad Apps section. Its a sticky at the very top called apps for people in IT. At my work we have an electronic sign in page to clock in every morning and clock out every afternoon and I can do it on my iPad. I also use my iPad for creating new incident tickets and checking of ones that have been completed. Remoting into the servers no longer requires running across buildings or finding the nearest computer, I can even do it while away via VPN on the iPad where ever I'm at. Going through emails is a breeze and its great having meeting invitations automatically ad into my calendar when someone sends me one.
Today I just re-inventoried all our equipment with the app HanDBase.
You will defiantly want to look into the remote desktop apps like WinAdmin or iTap RDP/iTap VNC.
and the Twit Pad app. if your in IT you probably already know about Leo Laporte and TWiT, if not check out
http://live.twit.tv for some awesome webcast.(Security Now is my favorite) you can also download them in iTunes for free under the podcast section.