When using WiFi you must be within range of a wireless network or at a "hotspot."
* At home or work, if there's a wireless router set up and it supports 802.11b then you can connect to the net from your PDA. If the network is password protected then you'll have to authenticate yourself (process depends on the setups) first.
* Thousands of businesses, such as airports, Starbucks, bowling alleys, etc have Hotspots (localized wireless internet) set up. Each one can control whether or not it's free. McDonalds, for instance, charges by the hour while others give it away to customers as an incentive to go there.
* Please, please, please be careful when connecting via WiFi for two reasons:
1.) If you connect to a network that you do not have permission to use you can be charged with theft of WiFi.
2.) Logging onto unknown networks can be potentially dangerous...the owner could have set up an Evil Twin (google that) that they use to intercept your personal information.
In short, though, you need to be within range of such a wireless offering...there is no 'nationwide' access at this time. Some cities, such as Google's hometown, are launching city-wide WiFi service, though, so it may not be long.
Okay, I lied too. I could make a couple hundred software recommendations (I test software on a fairly regular basis), but some of the top suggestions would be:
1.) Acrobat Reader (Free): Free reader from Adobe so you can read your PDF documents on the go.
2.) Airscanner Mobile (Free): They offer free antivirus and firewall software for the PPC. There isn't much of a threat to the PDA yet, but it never hurts to be prepared.
3.) SPB Finance ($25): The best money-management software for the PDA I've encountered, it syncs with both Microsoft Money and Quicken. Microsoft also offers a free version of MS Money which, while limited, still gets the job done.
4.) Mapopolis (per-map): Mapping software that also supports GPS receivers...never get lost again.
5.) Resco Explorer ($25): Replace the standard File Explorer with something much more reminiscent of what you'd find in Windows XP and then some.
6.) NiceStart: Replace the standard logon screen with a more visually-appealing and customizable one. it also possess the ability to lock down for XX minutes/hours or even wipe all data after XX number of incorrect access attempts...a major boost in security.
7.) Wisbar Advanced: Skin the entire interface to your liking. Sorry, but this is one area that is drastically lacking, so I consider Wisbar a must.
If there's anything in particular you're looking for, just ask.
Hope this helps,