It seems that you can't browse with just wifi anymore by default. I bought the flip to use with wi-fi many months ago, but would not spend $25 a month for a data service. It took some work, but I got wifi to work on the Flip.
![Thumbs Up](http://www.blackberryforums.com/images/smilies/thumbs_up.gif)
It was a simple as configuring the browser to use the hotspot browser.
Then came the 503 error to which the supposed solution is to reload the software.
![Thumbs Down](http://www.blackberryforums.com/images/smilies/thumbs_down.gif)
This killed my wifi browsing.
![Thumbs Down](http://www.blackberryforums.com/images/smilies/thumbs_down.gif)
I wasted some time and gave up.
Today I decided to waste a couple hours with T-Mobile support.
![Sad](http://www.blackberryforums.com/images/smilies/icon_sad.gif)
The third call yielded an intelligent support rep
![Smile](http://www.blackberryforums.com/images/smilies/icon_smile.gif)
who explained to me that they allowed the wifi access for a while and now require a data plan. Because my phone once worked and no longer worked, she explained why this happened and how to work around it.
She said that the wifi browsing looks for a "service book" before allowing browsing. I lost that "service book" by updating my software.
![Thumbs Down](http://www.blackberryforums.com/images/smilies/thumbs_down.gif)
To add the service book, you can add the data services and then cancel them.
![Thumbs Up](http://www.blackberryforums.com/images/smilies/thumbs_up.gif)
This should allow you to browse the Internet with wifi. It hasn't activated yet, so I can't verify this.
Of course there must be some way to put a "service book" on a blackberry, at least an unlocked one, with the right know how. For me ordering and cancelling is a good enough solution.