Check out this link on the photography board...
http://www.disboards.com/showthread.php?t=1144547for many unique ideas. (Edited to fix the link that as for some reason not working!)
There was also another poster on that board who set up a "scavenger hunt" for her pics on her Disney trip. She choose 2 topics for each day of her trip, and each morning she would pick "two out of the hat" so to speak
Things like
Signs (one of my favorites- parking lot signs, ride signs, building signs, billboards (I am local and drive so I take pics of the Disney billboards on the way) bathroom signs (the ones on the outside of the doors) you would be surprised how many different ones there are.
Architecture - instead of taking the whole castle pick a feature and take a close up. Worldshow case is a great place for this.
Look up and down - not just straight ahead. Look at things from different angles - even from the ground!!
Pics of CMs - other than characters - different costumes in Worldshow case, CMs at the rides.
Transportation- Trams from the parking lots, monorails, Disney buses (there are some with ride advertisements on them now), Magical Express busses,
Disney Cruise Line buses, monorails, ferry boats, and the different types of Main Street USA transportation that can be found.
Pics of a
favorite meal or drink....
Trash cans & Lighting fixtures - again there are so many different themes
Store displays
Hats - on folks or silly hats in the stores. Instead of you DD in front of the castle - take her pic with a funny hat on her head!
Flowers -
"Wildlife" - the bunnies, squirrels, ducks, birds, etc.
Have fun and think outside the box!!! If you are using digital - experiment - you can always delete it if it doesn't "work"!
I live locally to WDW and spend lots of time at the parks, and I still come home with new and different shots each visit....
2) Definitely ask passerbys or CMs to take your pics. I am forever offering to take family photos when I see Dad lining everyone up to take a pic without himself!