I am thinking about upgrading to DSL and was wondering If you can connect the wireless modem that it uses? if So How do you do it? do you just put the IP addess in the PSP?
If you get an adsl wireless router then yes you can use it.
When you set up the routers security (i strongly recommend not leaving the network unencrypted), just write down the WEP key you use somewhere (the routers manual will tell you how to set it up).
Once you have your router set up and your internet connection has been activated by your ISP you can just search for wireless networks on you psp, select your router (if you happen to see others, not just your network) and enter the WEP key when it asks.