One of the favorite features of Gowalla is about to pass a big milestone: we’re mere days away from having the 500,000th photo uploaded to Gowalla!

The ability to upload photos from your favorite Spots, Trips and events is only a few months old, but it has quickly become one of the most-used features on Gowalla. We want to take a moment to say “Rock on, you crazy photogs!” Not only that, we want to celebrate with some fun prizes! So here’s the skinny: We’re giving away some groovy goodies in the coming days for photos on Gowalla. For starters, the 500,000th photo will earn its taker a rad prize package filled with Gowalla swag and some photography-related goodies (we’re working on having confetti fall from the sky over said photo-taker’s head, too, but that’s more difficult than we first thought).

We’re also looking for some of the funnest, sharpest, most well-composed, ultra-interesting photos from the first 500,000 and doling out some loot for those, too. What kind of loot, you ask? Well, we know there will be some awesome Gowalla tees, Gowalla-branded Field Notes memobooks, and iTunes cards (depending on your home country), but we’re also racheting it up a not with some great other prizes:

• Flickr Pro memberships
• Lomography Diana with Instant Back camera kit
• And one lucky shutterbug will get a Leica V-LUX digital camera! (Sadly, Gowalla employees are ineligible to win this sick 12MP wide-angle camera =^)

500,000 photos is a lot of photos to go through, so we need your help: Do you have a photo on Gowalla you’re super-proud of? Have you noticed a photo on someone else’s Passport page or in a Spot view that just knocked your socks off? Then tell us about it! Post a link here in the comments, shoot us an email, or tell the world on Twitter! We’ll be updating this post to include some of the lucky Gowalla photogs who will be getting goodies.

WINNER UPDATE #6 We’re getting super close to No. 500,000, so time to give out one of the BIG prize packages! The winner of the Diana with Instant Back (and other assorted goodies) has way too many photos to choose from to pick a winner. In fact, only two people on Gowalla have more photos than Lianne, but don’t think her 765 are hit or miss, as the whole feed is quite impressive! (It sure doesn’t hurt that she’s in one of the most beautiful locales in the world, Hawaii.) It’s hard not to live vicariously through her great set of photos on Gowalla. Here are a few to get you started:

Ala Moana Beach & Park

Rainbow Falls State Park

Foster Botanical Garden

Diamond Head Lighthouse

Well done, Lianne! Thanks for your excellent contributions to the photo collection on Gowalla!

WINNER UPDATE #5 Stendec just got a Flickr Pro account for this beautiful shot of Link Trail Summit. Way to get out with Gowalla!

WINNER UPDATE #4 This excellent photo of a countryside manor just won Petr a Flickr Pro account and a sweet Gowalla tee!

WINNER UPDATE #3 Jon snapped this groovy rooftop shot and just won an iTunes cert and Gowalla tee!

WINNER UPDATE #2 Gowalla is best when shared with friends. Ivan just won a Flickr Pro membership and a Gowalla tee for his fun action shots taken with some friends playing basketball!

WINNER UPDATE #1 Shane snapped a great shot of the Lone Cypress at Pebble Beach, and we’ve just sent him an iTunes certificate for $30 (as well as a t-shirt and some stickers to follow)! Check out this beaut: