You did not mention if this was going to be a kid party or mixed with family. I assume the latter.
We tend to do themed parties.
We had a 5 yr old Pirate party with pin the patch on the pirate and a treasure chest hunt (complete with a map by a REAL pirate).
We had another 5 yr old Ghost Buster party (January) where I made Ghostbuster shirts for all the kids, played with slimey food and had the kids pose for pictures in which Slimer magically appeared in the pic upon development. (My husband is a photoshop whiz!)
Our 6 year old Curious George Party included bobbing for bananas, pin the tail on the monkey, and storytime (done by my friend who is a professional actress). That party was crazy--action packed and 15 kids! Not enough adult help either. That is definitely a plus.
At that party, we asked for NO GIFTS. We collected donations for Crisis Nursery. We got money, checks and actual stuff. Then, with the money, my son went shopping with the Crisis Nursery Wish List and got to pick out things for the other kids. Now, at first the suggestion to not have gifts was not accepted, but when I asked him what he wanted that he was not already going to get from us or the grandparents, he could not think of anything. I don't know how much he got out of it, and we are not doing it again this year, but he happily and graciously delivered the stuff to Crisis Nursery. He chose to give to kids, not animals or any other cause, and I think the only thing that was sad is that he did not actually get to see any kids, just an office, but I was really moved by it.
For this year we are doing a weather party. We will make weather globes, weather t-shirts, and doing experiments. We will be putting cheese and toppings on the pizza like a storm, and the cake will be a tornado. ( I am attempting it myself, so we'll see.) When people ask what he wants, I tell them just get him a gift certificate for Target, because he would like an MP3 player to use on the bus. We did thing for my 5 year old in January, and he was able to go to Target and purchase 2 of the toys that he really wanted, but that were too expensive to expect friends to buy.
I know I wrote a lot. Hope there is something in there that gives you some help and ideas. Good luck.