when we were there last year i made up "pillow gifts" for my kids (and sometimes dh and i! LOL) for every morning when they woke up... the gifts were inexpensive and easy to carry...
we all received disney tee shirts that i bought at disneydirect.com
kids got princess and pooh cameras bought at target
small stuffed mickey/minnie keychains bought at
disney store (on sale)
little lilo and stitch tins w/candies in them
some pins that i bought on ebay
underwater camera for the day we were going to water park (bought at target)
water yoyos from dollar store
and on their last day dd got a disney cd and ds got a disney gameboy game, for the plane ride home!
there were a few other small gifts that i just cannot remember off the top of my head...
the "mystery" of how the gifts were delivered was awesome... i also found it elminated some of the "gimme get me buy me i wants" 'cause if they asked for something in the park, i would remind them what if that's what mickey was going to bring you tonight
plus, i wrapped each gift in a colored paper lunch bag and made labels on the computer w/a note and signing each gift from a specific character (i.e. water yoyos from tigger 'cause they both bounce; camera from character on the package; underwater camera from nemo; etc)
it was great fun, low budget and well worth the time/energy it took to plan and carry out!
Each morning, I would leave their gift in front of our hotel door (on the inside) and they thought that Mickey left the gifts for them. To this day, they still think that Mickey left the gifts for them. 
