I already have a T-Mobile phone and looked into getting one of these without having to go for a new contract - to just swap the SIM between the modem and my phone.

They have no objections to using the phone contract SIM in the modem, but according to their telesales people you HAVE to buy a contract with it - its just not available without.

That means a new SIM.

That means another 12 mth deal.

So lets roughly work out the REAL cost - £30 + at least £15 x 12 = £210 minimum for the year.

I'm already paying them near that figure right now.

That's no good for me.

I don't understand why the carriers won't sell these devices in UK on a pre-paid basis. Surely ad hoc usage is the whole point?

In South Africa, for example, you can walk into a Vodacom shop, pay about £180, and come out with a Voda branded HSDPA modem with a pre-paid SIM.

It's blinding fast on a good day and the best part is, data costs just 1.5p per Mb.

To slightly elaborate on a point in this piece. This modem supports HSDPA 3.6mbps d/l. In practice, you can conceivably get around 2mbps in many locations on T-Mobile. If you are lucky enough to be using exclusively within range of a capable cell you could get up to 3.1mbps d/l which is not half bad!

T-Mobile has only rolled out the 1.8Mb version of HSDPA so far, so that's the best you'll get regardless of what the hardware can do. I'm seeing up to about 1.5Mb/s, depending on how busy the network is, on my 3.6Mb/s-capable Sierra Wireless 875.

Incidentally, if you have a PC-Card slot, the Sierra 875 can be had Cingular-branded but unlocked from the US cheaply on eBay. Mine was £78 all-in.