Just upgraded my Sony PSP to firmware 2.0 and tested the new built in browser - it works wery well.
The screen is a lot better than this photo leads you to belive, but if you have used the PSP you know how good the screen is. Still, 480x272 is quite a small screen but the two "fit to screen" modes available in the browser do a decent job at compensating for the limited resolution. And 480x272 is certainly a lot better than 320x240 on old PocketPC devices or the tiny screens of Symbian Series 60 devices.
And I love the default font, it is really estetic.
Still, the PSP will not replace my Nokia 9500 when it comes to browsing. The 9500 has a bigger screen, both in size (width) and resolution (640 pixels compared to the PSP's 480). The 9500 also has a keyboard (witch is the reason I was willing to spend such a lot of money on it) and it allways works - regardless if there is GSM, GPRS, Edge or WiFi coverage.
But considering how much cheaper the PSP is, this is indeed a great device. No other device offers you such a good mobile surfing experience at this price.
Some people have complained that the PSP does not have a touchscreen but I don't think it would make the surfing experience any better - the analog controller is a great mouse replacement and scrolling with keys is easy and does not require a scrollbar.