I LOVE baby showers. I've found lots of fun ideas online but here are a couple. For my shower, friends did a "Price is Right" game -- a table full of baby items (wipes, diapers, cream, bottles, toys, etc.) -- and the mommy has to guess the right price, with help from the audience, and she "wins" all the items. :) I've also hosted a couple showers, so here are some other thoughts.
Decorating idea -- hang a clothes line and use clothes pins to hang baby outfits, onesies, socks, etc. It makes a nice backdrop, especially hanging over the gift table.
Another use for clothes pins -- everyone gets one clipped to them when they arrive. Every time someone says the word "baby" (or even the baby's name, if that's known) her clothes pin must be surrendered. So if I catch Mary saying "baby," I take her clothes pin and clip it to my shirt. At the end of the shower, the person with the most clothes pins wins a prize.
Also, diaper cakes are really cute and actually not as hard to make as you might think. It takes about 2 packs of small diapers, lots of rubber bands and some ribbons. You can find video tutorials on YouTube that show you exactly how to do it.
Food -- for something different, you could try a brunch with egg/sausage casserole, muffins, etc. That stuff is easy to make in big batches, affordable and yummy. Cupcakes are cute with the cupcake "tree"-type displays and less intimidating than cake if you are making it yourself. :)
Have fun!