3G Router User
Yes, there are a number of vendors making routers that fit that description. See the following link for a number of them:
http://www.evdoinfo.com/component/option,com_wrapper/Itemid,115/
Does anybody make a modem/router (gateway) with a USB connection so that I don't have to use an ADSL (telephone line) for broadband? In other words, can I connect a mobile 3G dongle and still have my home network?
Not for the faint-hearted but certainly a budget option:
Take an ASUS wireless router, most of which come with one or more USB ports. Replace the firmware with open-source OpenWRT (www.openwrt.org).
Connect a Nokia mobile phone with the USB cable provided to the ASUS (I used an old 6680, but new-fangled HSDPA models like N95 should work as well and they give you more oomph). The Nokia acts as the modem and can be controlled with the venerable AT command set.
Install and configure ACM driver and PPP on OpenWRT. This is the hard bit and requires a fair deal of patience/smokes/coffee/wine and not to forget, Linux admin skills. Guidance and help is available on the OpenWRT forums.
There is 2 that I know of that are a great deal cheaper the the ones suggested.
Draytek Vigor2800VG http://www.broadbandbuyer.co.uk/Shop/ShopDetail.asp?ProductID=2690 hurry though as it is just about to be replaced by a updated more expensive model that will do the same job. http://www.draytek.co.uk/products/vigor2820.html
These Vigor routers are the small business choice as they are very reliable and have VPN access as standard.
The other one is the Linksys WRT54G3G 54Mbps Wireless Broadband Router for 3G/UMTS http://www.broadbandbuyer.co.uk/Shop/ShopDetail.asp?ProductID=3193 don't know how reliable this one is.
123Telecom (www.123telecom.co.uk) do a complete solution called Dual Route which includes a standard ADSL2 compliant router which has a 3G Datacard slot, the datacard, and an airtime package for main use or just for emergency backup. They also have a USB dongle 3G version available, although this isnt mentioned on their website. I think the router may even be free with an annual contract paid up front.
Sarian (http://www.sarian.co.uk) do some nice routers, in various combinations of wired (ISDN, xDSL, etc) and GPRS/3G/HSDPA. They're mainly aimed at remote point-of-sale and telemetry apps. One really nice feature is that most can support 2 SIMs so can failover to a second network if the first one goes down. They've just been bought by Digi, so it'll be interesting to see how things pan out on that.
A bit more expensively, Cisco have just launched a SOHO router (the 880 series IIRC) and one of those supports GPRS/3G. Otherwise Cisco can sell you an 1800 series router with a 3G interface card (£££).
Alternatively, Checkpoint's UTM-1 Edge firewall/router box can take a USB dongle and use that as a backup link.
HTH, and good luck.