One of the problems with renting a photobooth outside is that the computer monitors are very difficutl to see in the direct sunlight. There are companies that make specialized outdoor monitors for 20x the cost of a regular monitor.
For example a normal 19″ monitor that is on sale for $100 would probably cost $2000 for an outdoor viewable monitor.
There are reasonably priced alterantives though. Fujitsu and Motion computing both offer tablet PC’s that can easily be viewed outside. These tablets can be bought used for $100 to $300 in price. Unfortunatley the largest size they come in is about 12″.
Fujitsu makes many models some of them are as follows:
st4121 around $100
ST5022 1.1ghz around $300
Often times these older tablets can be missing parts or accessories which can be bought from
Fujitsu by calling their sales number 1 877-299-5445.
Motion Computing also has tablet PC’s that can be viewed outside. Unfortunately for photobooth usage their tablets come in both outdoor and INDOOR ONLY configurations, so you need to double check what you are getting for your photobooth.
M1300, M1400, M1600, and M1700 are the most common. The last two use smaller hard to find 1.8″ hard drives though.
Lastly there are many other tablet pc’s that are outdoor viewable. Panasonic makes a line called the toughbook. Models that can be viewed outside include the 19, 74, cf-74,w2 and H1.
All of this information is based on web research. I have not actually used one of these displays in my photobooth yet.