I own a Sharp Zaurus and a Palm Treo 650 along with a WiFi card for both. I never use WiFi. Here’s why.
There are several scenarios where you think it’ll be useful to have WiFi on your phone, either for e-mail, browsing or VoIP.
At Home or Work
Once the novelty wears off, you will realize that the computer in the corner is much better suited for internet and e-mail usage. If you want to curl up on the couch or wander the house doing chores while talking to your Mom via VoIP, add a $20 bluetooth dongle onto your computer, router or NSLU2 and use that instead; you’ll double your battery life.
At a Friend’s House
Most friends have computers they’ll let you borrow. Extensive surfing or VoIP’ing is antisocial, you won’t be taking advantage of that as much as you think you will.
Out on the street
By the time you find a free, open WiFi hotspot, your battery will be dead. GPRS is so much more reliable that once you hook it up, you’ll just end up using that instead.
I spent two months in Europe and blogged every day for the entire trip using my Treo 650 and a bluetooth keyboard. I brought along the WiFi adaptor and never used it because it was such a pain to find and connect to a hot spot. Instead, I transferred articles from the Treo to computers in Internet Cafe’s via the SD card and a USB adaptor.
At a coffeeshop to work outside the office
A laptop is so much more usable that you’ll end up lugging the heavy thing to the coffeeshop rather than taking along just your phone.
WiFi is nice to have, but it shouldn’t significantly affect purchase decisions. Don’t ignore beautiful phones like the Neo1973 or Treos just because they don’t have WiFi.