I think it's great that you're happy with your netbook-in-a-satchel solution. That does not mean, however, that smartphones are merely toys. Maybe they are to you and some others, but plenty of people get real use from them. My Android phone was roughly $130 (with a 2 year service agreement, the way most cell phones are sold in the US), and I get plenty of non-toy use from it:
E-mail (so if I get something important, I see it right away).
Contact list seamlessly synchronized with my Gmail account.
Calendar/scheduler/task list that also stays synchronized with my Gmail account.
Epocrates drug reference for quickly researching medications (I'm a nurse).
Weather Channel app for checking weather updates.
Barcode scanner with a price checker--nice for when I see something in a store and want to know if it's worth buying there if I should buy elsewhere.
Google maps (with GPS)--ironically, this was more useful during a time I spent car-less, since it includes public transportation routes with bus times.
Remote app that lets me use my phone as a remote control for my laptop when it's connected to my TV as a media center.
Grocery list app (which can be synchronized between computer and phone)--more convenient and less wasteful than written shopping lists.
Of course, I'm pretty happy with the toy uses too. One of my least favorite activities--waiting--has been converted into one of my more favorite activities--reading shit on the net. Much of the time I'm using my phone, a netbook would be at least inconvenient, and more often completely impractical. And for the times I need an actual mobile computer, I'd much rather have my full-sized laptop than a netbook.