I'd personally buy a ASUS T91, or maybe a MID.
For those of you who don't know, the ASUS T91 is a netbook with tablet's screen. So it does anything a netbook does and also what a tablet does. It is an inch thick, and has less runtime, but it does have more storage, a real keyboard, costs less (check the prices yourself). Too bad other companies doesn't spend more money making hype and convincing the public that they need another piece of technology controlling their lives.
The Mobile Internet devices are also a good alternative. For example the Archos 5 (you can also get it with 3G). It's smaller, can surf the web, has Flash, and so on.