Apple AirPort Express share internet with USB dongle?

Hi Guys

First thread, so go easy ;-)

Firstly, please forgive my ignorance, I realise this is predominantly American used forum & not sure if you use or have 3g USB dongles, so link below to the service I use: (dongle is Hauwei E180)
three.ie - Help & Support - Broadband & Technical Help

Considering getting a new iMac & getting rid of this powerbook.

Long story short, have a question....

If I get an AirPort Express, then connect to the internet on the iMac
(Using a "Three" 3G USB dongle) not an Ethernet cable or anything similar
Is it possible to share the internet access using the AirPort express to devices such as my iPhone?

Someone said it is possible, someone else said it wasn't, someone else said it was, but with an extra router or something.

Could you let me know what you think....and if it is with the extra router, what one would you recommend, preferably one on the likes of amazon so it can be shipped to Ireland.

Cheers
Spy

Does anyone have any suggestions?

You can put the host machine in ad hoc mode and share the internet connection using the built in AirPort card in it. This will likely be cumbersome and is best suited for temporary networks.

Instead, I would recommend going back to your carrier to see if they have any "MyFi" solutions to replace your adapter. All the major carriers in the states are now selling these devices, which combine a wireless router and a cellular-based 3G modem into one device. Typically you can connect up to 4 machines to them.