I have been impressed with Opera mini running on my Palm TX and my SonyEricsson T630 phone. It appears other people have been as well - here's a quote from http://tamspalm.tamoggemon.com/
"Overall, Opera Mini 2 worked ok on my Palm Tungsten T3. The browser obviously is different from Web Pro and Blazer, as it doesnt even attempt to recreate the original page layout - this reduces data transfer volume and makes browsing hell fast(almost as fast as on my desktop). 5way control works really well too - no need to use the stylus when surfing! If you are on a GPRS contract, look at this free browser - it could save you money!"