The other day, I downloaded the second beta of Firefox 3. I also downloaded the Mac theme. I love both. The mac theme is especially nice; it adds a brushed metal look with Safari-like buttons. I've only had one bug having to do with two-fingered scrolling of the bookmark pull-down list, and it's only a sporadic problem. The memory usage of this browser is a welcome change from Safari 3. I was having massive memory leaks on Safari, sometimes ballooning to 750-850 MBs of real memory being used after a few hours. Right now, I've had Firefox 3 open for at least a day and with 10 tabs up, it's using 142 MBs of memory.