I noticed you can change the browser emulation from 'Blackberry' to other things such as 'Openwave', 'Microsoft IE', 'Netscape', etc.

What would be the differences? Is there a reason to try something else besides the default BB emulation?

Certain sites are looking for certain browsers to provide certain functions.... this setting would presumably would tell the site you're visiting that "hey I'm a compatible bowser".

Just like when you do your online banking, the bank is looking for a certain version of the browser or newer....