As a longtime T300 owner there are a number of sites that drive me crazy; for many of us the upgrade decision will be based on the new Blazer. Post your sites here. My pet peeves:

1) http://newyork.citysearch.com
-On the T300 you see the "Search" button, but not the text entry box next to it. Does it work on Blazer 3.0?
-Scenario: You're in midtown and want to find the nearest good Italian restaurant. And your Vindigo trial has elapsed.

2) Any website with PDFs on it, such as the NJ transit site (http://www.njtransit.org); specifically the PDF itself ("http://www.njtransit.com/pdf/rail/r0090.pdf").
-It'd be great if Blazer 3.0 could natively open these, but if not maybe you can "save" it and use Adobe Reader for Palm OS? Does this work?
-Scenario: You missed the train and don't want to walk all the way downstairs to the ticket office and find out the next one.

3) Other travel sites that people can think of.
-Scenario: A snowstorm is delaying all the flights, and while the 800 #s are busy and the gate agent lines are twenty deep, you're furiously seaching travelocity.com with your handheld web browser. Many times the treo has saved me as I've nabbed one of the last rental cars or hotel rooms available. As I recall travelocity works "OK", but OAG or Expedia or one of the other ones didn't work well.

4) Pop-up windows, like logging into my online banking site (Chase.com) or Outlook for Web Access. Commenting on a blog (e.g., boro6.com).

Chime in!