I've got an Archos 604 PVR which comes with a stupid proprietary USB connector to charge/transfer data with. If I want to charge from the mains I need to shell out for a docking station but could I instead use one of these... http://www.expansys.com/zoompic.aspx?type=item&i=101717 ?

And are they safe? i.e. all nicely regulated?

Should be good enough. I have several similar devices here, and they're all (1) small, (2) light weight, and (3) regulated +5VDC output.

Cheers

You might find some of the iPod adapters on ebay are cheaper, if you don't need the multi-country plug things, eg:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280084756587

...or for car use this is ok:

http://www.ledshoppe.com/Product/com/CA4003.htm
(all their products include postage in the prices!)

If you have a spare 12v adapter you could make up a cigar lighter adapter socket lead to work with that unit above.

Yeah, that proprietary cable is my least favorite thing about the 604. I have the travel docking station (with power and USB/USB OTG ports), and I basically have to carry that wherever I go, because it's easier to carry that adapter and rely on having a miniUSB cable available than it is to carry the proprietary cable around. Basically you have to carry one or the other.

Anyway, I'd like to hear your impressions of the device. I have the 604 Wifi and I'm a pretty big fan.