3G internet and dongle questions

[freebooter]

I want to get a 3G sim and dongle to use with a netbook. Never used one before and don't know much about them so I have some basic questions.

I have seen sims available on ebay offering three 3G for 90 days which sounds ideal. Are these sort of deals ready to go and just use and throw away when the credit is used up or are they ones you top up like a payg phone sim? Do I need to set up an account with the provider?

Dongles seem to vary in price on ebay a lot. Is there much difference between them and if so what should I be looking for? I see there are unlocked ones but they tend to be more expensive.

Any other tips or advice welcome.

thanks

 

[freebooter]

I bought one of the 1GB sims from ebay to try and I am using it in my phone and tethering to my netbook to start with. It works but the signal is really poor. Looking at the three coverage map I am in an area that is ranked for outdoor use only so not surprising but still annoying.

I didn't need to register - it just worked straight away. Is there a way of finding out how much credit is left without registering with three? If I am going to buy new sims instead of topping up I don't want to have to register each one.