Mister Panda,
You don't say where you're from originally, but let's say it's one of the states with a major PBS station. That station has a subscription for which they're always requesting membership sign-up. When you're a member, you're supporting public television. In the States, this is optional. In the UK, it's not. If you watch anything at all on the BBC, watched BBC America back home, listen to BBC radio, listen to BBC World radio when you're not here, or visit their numerous websites, you're getting the benefits of the tax. It's free for the elderly and disabled, reduced rates are available for the poor, a Black & White license is cheaper than the standard (for which you can only use it with a B&W telly), and you always have the option of not having a telly - radio only is free.
If you never watch/listen/surf the BBC, but still own a telly, you alas still have to pay the tax.
The way they find out if you're not paying is to send vans around that can sense the radiation given off by CRT tubes (and now Plasma TVs). If it senses the radiation coming from your house, but you don't have a license, you get sent a £1,000 fine. It's cheaper to pay the tax, but if you know when they're coming to your neighborhood, you can always arrange to have the TV unused for several hours beforehand. I am surprised no enterprising young person has set up such a website/text-messaging alert service (for a subscription fee...) already.
Historically, it's been here since BBC first started television broadcasts. It's unlikely that a toaster tax will evolve, though an IPod "tax" is very likely to, added on to the pay-per-download from which the artists get their royalties.