When I use wifi I use the hotspot browser. How I do it is I open my browser, go to bookmarks page and then click on wifi hotspot log in, I get a message saying that I am connected (my home network) hit menu bookmarks again and select a page I want to go to or select 'go to' to type an address. There is a noticable speed difference.
There may be an easier method but I don't use wifi a great deal.
Doing it this way I keep my internet browser as my default without having to change it all the time.
I have :-
o2 wap browser.
No sign of a blackberry browser anywhere.
I can also use the hotspot browser when out and about to sign into BT openzones wifi services for free as part of my broadband package I have log in details for this which appear when connected.
I hope this helps and if someone has a better way hopefully they will post it