Dell Axim x30 is a powerful pocket-pc. Here are some links if you want some basic information.

1. CNET Review for Dell Axim x30
2. PC Magazine review for Dell Axim x30
3. Dell Axim handheld page
   

Here are some practical uses I have found for this in addition to general stuff you would expect from a PDA/Pocket PC. Even though I have been using x30, I do not believe there is significant difference in later versions.

1. It is a cool MP3 Player with a good headset. The built-in memory in my x30 is only 64MB and most of it is already occupied. But I normally use an SD-Card to store my music and play with this. It is not as cool as an ipod but may be somewhat better than listening on a cell-phone.
2. With wireless access, it can be a skype phone. I am surprised how good the quality of the call is even without a headset. This could be useful, if you already use skype and do not have multiple lines and your phone is tied up. Obviously you would need a high speed connection to have good quality speaker phone. All you need is to download skype version for pocket PC and it should work like the regular skype.
   
3. Dell documentation is not very clear on how to setup ActiveSync via wireless. Here is what worked for me
• First set up and make sure you are able to get connected to internet using either My ISP or My work connection. You would need a router that is connected to DSL and may need to enter your WPA encryption key if you use encryption. (You should be using encryption with any wireless access )
• Then select ActiveSync->Tools->Options->PC Synchonization Options as 'BlueToothActiveSync' (The default for this is USB default)
  
• On the ActiveSync on your PC, you check by right clicking and selecting connection settings, "Allow Network and Remote Access".
  
• In Settings->Connections->Select Networks select the connection name as the one to connect for "Programs that automatically connect to a private network should use the network. For example if you used "My ISP" as the one your pocketpc uses to connect the network, you should use "My ISP".
• Offline browsing using avantgo. You would need to setup an account and set the feed you want. This will be good if you are waiting for something.
• You could use this as a photo-viewer with some software.