The PSP drove me nuts when it came to entering URLs. The 770's better, but it has its flaws.

1) Keyboard. The Mylo has one, and it definitely make a difference.
2) Performance. I've used similarly powered PCs (Toshiba Libretto 110CT, for one,) and when pared down to the 770's functionality, they were snappier.
3) Email. I'm not even going to get into how much the 770's email client upsets me.

However, it's $350, has WiFi AND Bluetooth, and runs a ton of Linux apps, which is great. I have to ask, though, how often do you need to pair the 770 to your phone to do something that your phone can't already do on its own? Many BT-capable phones are acceptable IM clients in a pinch, WAP sites aren't great, but again, they can do the job. There just aren't a whole lot of uses for the 770 when there's no WiFi, which may justify the Mylo's lack of Bluetooth. Of course that allows some of the cost to go to the keyboard, even if that doesn't excuse the screen.

Simply enough, the 770's a little too much for what it can do comfortably. Trim out the BT, add a slide-out keyboard, ditch the bells and whistles and third-party app capability, and it's closer to a marketable device, but then few of us would own it. I adore the hackability, as it's rapidly become my digital Swiss Army Knife, but while I'm okay with a Swiss Army Knife, other people just want a decent pair of scissors.

As for audio, it can't hold enough MP3s for my tastes, nor is it trivially simple to dump video onto it. (Yes, I can drag and drop, but my iPod syncs automatically, whether iTunes is loaded or not.) It's not an ideal PMP unless it can hold a 1.8" HDD, or support something closer to 8GB of flash. It's not a perfect mobile web browser for my forum-hopping needs unless it has a solid integrated keyboard. The control layout isn't great for games, for that matter. It can do all of these things, but it doesn't necessarily do them well.

It does, however, start up VERY quickly, sip very little power, and pack a hell of a lot of display in a very portable package. I can't carry a Libretto with me at all times, or a Vega UMPC, or the Kohjinsha submini laptop. I can, however, bust out the 770 on a whim, check on gmail, zip through a few forums, and even stream some audio in no time flat.

If I were less of a geek, I wouldn't bother with any of this. Luckily for Nokia, I'm exactly that much of a geek, and have no problem looking past the obvious warts of the 770 to take advantage of what I *can* do with it. Unfortunately for Nokia, I don't think there are enough geeks to support the device without some major updates in the next iteration of the hardware.