There are some cables you can use. Depends on what model iPad you have and what interface is on the projector. You could also get a router to take with you and set up your wifi connection. There's some portable routers.
You can connect via a cable or wireless using an Apple TV.
http://ipad.about.com/od/iPad_Guide/a/How-To-Connect-Your-Ipad-To-Your-Tv.htmhttp://ipad.about.com/od/iPad_Guide/a/How-To-Connect-Your-Ipad-To-Your-Tv.htm
Connect an iPad to a Television or Projector
http://www.everymac.com/systems/apple/ipad/ipad-faq/how-to-connect-ipad-to-tv-te levision-projector.htmlhttp://www.everymac.com/systems/apple/ipad/ipad-faq/how-to-connect-ipad-to-tv-te levision-projector.html
Connecting iPad iPhone or iPod to TV or Projector
http://www.disabled-world.com/assistivedevices/computer/ipad-tv.phphttp://www.disabled-world.com/assistivedevices/computer/ipad-tv.php
iPad Accessories: Connections for a TV or Projector
http://www.dummies.com/how-to/content/ipad-accessories-connections-for-a-tv-or-p rojector.htmlhttp://www.dummies.com/how-to/content/ipad-accessories-connections-for-a-tv-or-p rojector.html
You may be interested in AirPlay on the Apple TV:
http://www.apple.com/airplay/http://www.apple.com/airplay/
http://www.apple.com/airplay/http://www.apple.com/airplay/
Alternately, there are Apple Digital AV Adapters for hardwired connections:
http://support.apple.com/kb/ht4108http://support.apple.com/kb/ht4108
http://support.apple.com/kb/ht4108http://support.apple.com/kb/ht4108
Portable routers http://compnetworking.about.com/od/routers/tp/travel_routers.htm
Cheers, Tom 😉