Even though I have been using converged mobile devices for over a year, I still keep a dedicated PDA in my collection. The Dell Axim X51v is one of my favorite devices ever and I recently pulled it out and loaded up the latest ROM update along with some of my favorite applications and games. As I started to use the device again I had some questions and visited the site that covers everything related to the Dell Axim, Aximsite. This is quite an amazing community site with something over 135,800 members and over one million forum posts. If you have any questions related to PDAs, especially Dell Axim devices, then I highly recommend you visit Aximsite first before hounding your local geek for help. I get emails for help daily and use Aximsite as a reference to help people find detailed answers.
For questions related to devices with a phone integrated I personally visit Howard Forums and MoDaCo along with many other enthusiast sites. I have a list of approximately 40 RSS feeds for mobile enthusiast sites I visit on a daily basis to read the latest and greatest regarding mobile gadgets.