With Gowalla you can Discover, capture and share places and events with your friends.
From Gowalla Blog:
The beta release now includes photos and commenting on Spots, as well as better notification options. Trips and Items will be coming soon to Blackberry as well. Point your Blackberry browser to Gowalla.com and you’ll find the link to download the application for your phone. Alternately, you can download it to your desktop and then sync it to your device by visiting: http://bit.ly/BBdwnld
And finally, we need your help to create the best possibly Gowalla experience for Blackberry. You can lend a hand by posting your feedback and bug reports to our Gowalla for Blackberry support site or by dropping us a line at blackberry at gowalla.com. Thanks!
Visit the sign up page at Gawalla for BlackBerry HERE!