I picked up an ipad2 a while ago and have started to use it for my business. It is great to bring to meetings with prospective clients to show them pictures of my portfolio. I ran a wedding using the ipad and it worked out great. I have a long list of documents that I bring to an event - set up sheet, pick up list, return list, time line, vendor list, key contacts, transport schedule, hair and makeup schedule, seating plan and floor plan. I found that it was actually easier to find the right document from my ipad than trying to file through a list of paper documents on my clipboard. I keep an extra set of the documents in paper form at the event just in case something happens to the ipad.
Having all my documents on the ipad also helps when I have a consultation, so I can show prospective clients my work. I had a meeting last week with a client getting married in September and it was easy to discuss the time line and set up sheet just off the ipad. There are often a number of iterations to these, so I like not having to print out multiple copies for our various meetings.