Did you read my "Great Park Bag" post?!

Check it out b/c I found an AWESOME Park bag!!!I found the Diaper Dude messenger bag and that is what I'm taking this year! I was worried that my Donner bag would be STUFFED with the needs of four people...two children and two adults. So I went looking for a bag that that would be easily accessible, not too girly, and able to hold a fair amount of stuff without getting hugely heavy. It's got padding on the strap, pockets galore AND bottle holders! As in Diet Coke bottle holders!!

It's got fun colors and designs aimed at men and you would never know it was a diaper bag. It just looks like a messenger bag. I got mine at
www.travelingtikes.com for $49.99, shipping was free! (it's the lowest price on the web! The camo print bag I got was $65.99 in stores and online!) Their customer service department is AWESOME! Okay...now that my public service announcement is over...
...Like I said, I have an Overland Donner bag that I carried last year at the parks. It was GREAT! I love the bottle carriers on either side of the bag! (also fits an umbrella very nicely!) It's a great bag, roomy and sleek! I love the color choices too! You can get it for quite a bit less than at Zappos though. check E-bags. I got mine for way less than $57! If you google "ebags coupons" you can sometimes find 10%-20% off your purchase. The only thing I didn't like much about the Donner bag was that it started to feel really heavy after a little bit and the strap isn't cushioned. Of course that could be b/c I put a lot of stuff in it!
good luck!!!
PS-Zappos has Diaper Dude bags too...way over priced on their site, but you can look at several pictures of the bag to get an idea of what it looks like!