we are having lots of friends family and previous co workers with dinner at a country club and we have 4 hours plus this is a surprisefor her. I want ideas to make this be fun and memoriable for mom (loves to joke and have fun). What to do besides dinner and a DJ. What do you tell people as far as gifts. What to do please advise

we had a 80th birthday for my gram a few years ago we had someone gather as much information about her from when she was a child only good things. and they made it into a poem and framed it. then read it to her infront of the crowd. you could also invite people up to tell some funny things that she has done or had happen to her. We also got someone to take a big family photo of us all then each individual child of hers with their children. also take lots of extra pictures and make a big photo album for her as a surprise .

I saw an idea for a scrapbook for a mom-in-law's 60th bday on DIY's "Scrapbooking" - you could look up the episode at diynet.com.
My suggestion would be to find OLD pictures of mom and family, especially of mom as a child or young lady, and especially if they are few and far between (this may take some work contacting relatives). Scan them in, save them to a disk as a jpg file; I recommend about 300 or 400 dpi, and take the disks to Walmart. They will run them off for 29 cents a 4 x 6, and not too expensive for larger sizes.
Now, here's some ideas to do with those: Obviously they could be used as decorations, or you could put several in little photo albums (Dollar stores around here carry the plain small sized ones which could be decorated with stickers or ribbon roses, etc.) Depending on how many guests you have, these could be party favors or door prizes. They could also be prizes for games or you could mat and frame some of the nicer ones for prizes. I truly hope you can gather some old pics. If not, you can still use the family pics taken at the event as "future prizes", that is, give them an I.O.U. for a framed 8 x 10 of the group. Cut colored paper with decorative scissors and write in nice handwriting to make it pretty, or decorate some other way so it looks like a prize and not just an I.O.U.
A game might be to cut some extras into puzzles and compete to see who can assemble their pile the fastest, or just cut them into 3 or 4 pieces each, give each partygoer a piece, and have them find their other piece holders to make the whole picture. This might be a fun way to break the ice if there are a lot of family members attending who don't spend a lot of time together/know each other well, such as in a family reunion.
As to gifts, it would be nice if each guest could simply write down and bring a family memory, whether it is about your mother or even one of her parents or children. They can handwrite it on a piece of notebook paper, type it, or make it fancy and decorative (see scrapbook ideas again). In any case, they should be suitable for a scrapbook, and perhaps they can even send them to you ahead of time so you can assemble them into such. Then, I agree with the other poster, some might be read aloud at the celebration.
Another gift might be to make a memory box or shadowbox using some of her treasured things that are currently stored in such a way that she cannot enjoy them on a daily basis. Perhaps she has a silver evening bag that belonged to her mother, or her own baby spoon and christening gown, or a collection of Valentine cards from your dad, etc. If you can swipe something and make a nice memory box display that she can enjoy on the wall every day, that might be nice.
One other thing that comes to mind; I don't know why - perhaps she has a beloved piece of jewelry that she has not been able to wear because it needs repairing. You could have it fixed or reset as a gift. I have no idea why I thought of that, except maybe I'm thinking of some of my grandmother's jewelry.
Well, I may be way off track since you're doing the DJ thing; just some ideas that came to mind!

Thanks for the ideas. I am currently collecting pictures of my mom from friends and family and making an album. I think I will use one of your ideas and use some of the pictures as decoration. I was thinking of using picture table center peices of "funny" and "serious" pictures.

How did the 70th party go? I am in the process of planning a 79th for my father. any ideas would be helpful. THank you in advance.

CB