While many sites work just fine on a mobile device without creating a mobile version, there are some where a mobile version works much better than surfing to the original site. My favorites are listed below. You should be able to view the mobile version of each site by clicking the links at the end of each item.

1. Google Reader: Fast and easy access to RSS feeds. Since you're accessing the same data you'd access through a computer's web browser, you avoid syncing issues. It's missing a few features you'll find in the browser version, including the ability to email stories to friends, but the speed and ease of use are amazing. Bloglines Mobile does offer emailing capability - without an integrated address book, so you need to remember your friend's addresses - but falls short when it comes to consuming stories in a mobile friendly manner. Clicking a category immediately marks all stories in that category as read - even if they're never viewed on the device. http://www.google.com/reader/m/view/

2. Dodgeball - Dodgeball's mobile site provides much easier access to the restaurant directory, leading to more accurate check-ins. Oddly, the main Dodgeball site is about the least mobile friendly thing I've ever seen, so the mobile version is critical. However, it's missing the top-10 most recent and highest ranked Dodgeball users lists, which takes away from the coolness. I haven't seen much new development on the mobile or non-mobile site in months, so I'm trying to be content with the application as it exists today. http://www.dodgeball.com/mobile

3. Twitter - A fast and and easy way to update your Twitter status and read tweets from friends. It's a better interface for reading recent Tweets than being bombarded on your phone - especially for people who don't have threaded SMS messages. http://m.twitter.com

4. Amazon - Amazon's main site's pages are so huge, they'd take forever to load on a mobile device - if at all. Once logged in, making purchases using your main credit card and shipping address on file is a snap. Picking an appropriate category for your search helps a lot. I tend to use it to make impulse purchases of books I hear recommended on the radio while, um, waiting at a stop light. http://www.amazon.com/gp/aw/h.html

5. GoDaddy - Godaddy's mobile site is a great place to check the availability of domains that sound perfect after that 3rd pitcher of beer. http://www.godaddymobile.com

6. Ebay - Similar to Amazon, but better for random crap. I've used this mobile version of Ebay for some time now. The URL is ugly, so make sure to bookmark it after getting there the first time: http://wap2.bonfiremedia.com/ebayserver/servlet/Controller?bmsid=&Command=WapSearchMenu

7. Facebook - A great way to get a quick update on what's going on with your friends, update your status, review some pics, etc. While you can SMS your status updates to Facebook, the mobile site is a better option for consuming content. I receive friend and wall updates via SMS, and this is how I check them out when I'm away from my computer: http://m.facebook.com

8. Flickr - A great way to review recent activity on your photos, pull up a picture from your account to show a friend in a bar, or to show someone what a Yugo looks like. It's a bit over-optimized, showing only three thumbnail photos per page for search results, but other than that, it's a well designed mobile version of the photo site. http://m.flickr.com

9. Yahoo - This covers a LOT more than just search. Access tons of Yahoo services, including news, weather, your MyYahoo headlines, driving directions and Finance to name a few, from this mobile version of the portal. I'd recommend bookmarking your favorite sections within the portal that you find yourself going back to regularly rather than the homepage to speed things up a bit. http://m.yahoo.com

10. Google - The mobile version of Google search is a automatically attempts to mobile-optimize the pages you visit when clicking on a result (Google Reader and Bloglines do this as well). This doesn't always work as expected, but they do provide a link to view it in it's original state. That helps if you want to grab and email a URL to someone. You can build out a personalized Google homepage with news, weather, and finance information, which will save you a few clicks while slowing down the homepage load time. http://www.google.com/xhtml

11. Gmail - The mobile version of gmail provides faster access to your emails by providing easy navigation using power keys. It gives up a few features along the way, such as the ability to mark messages as spam, and a biggy - to select more than one message at a time for batch deletion, spam, etc. However, it is very fast for read functions since it has so much less code to load than the non-Ajax version of gmail.com. http://m.gmail.com

What are your favorites? Add them in the comments.