I'm able to get to the calltones page with my mogul (bookmarked from my 6700) but I am not sure how to get in there now and get that special id if you don't have it already. But basically you need to find a link to the sprint site through your phone (i believe with the proxy set correctly) and then go to the vision homepage link.
Here are the original instructions to getting it to work just in case:
This is a two-part hack. First, you have to setup the Sprint proxy. Second, you have to make the website think you're running on a supported phone.
PIE Hack
1. Download a registry editor (I used PHM Registry Editor ).
2. Kill PIE(pocket internet explorer) with task manager.
3. Navigate with your editor to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Curr entVersion\Internet Settings\5.0\User Agent
4. You will need to edit the following values:
(Default)=Mozilla/4.0
Compatible=compatible
Desc=Windows 98; PalmSource/hspr-H102; Blazer/4.0
Platform=Windows 98; PalmSource/hspr-H102; Blazer/4.0
UA-Language=Windows 98; PalmSource/hspr-H102; Blazer/4.0
Version=MSIE 6.0
Exit registry editor
Proxy Connection
5. Go back to the home screen. Press Start>>Settings>>Connections>>>Proxy
6. Press Menu then Add. Title it Sprint Proxy.
7.Fill in the following settings:
Connects From: The Internet
Connects To: WAP Network
Proxy (name : port): 68.28.31.33:80
Now Press Done.
8. Open PIE. Go to Menu>>Tools>Options
9. Select Network: Wap Network. Uncheck Automatically detect settings.
10. Go To
http://vision.sprintpcs.com
But.. going through this with my mogul I couldn't get it to bring up the sprint page with the id. so no luck so far with duplicating the process. but it does work with my bookmark.. so it must not be impossible??