Recently, AVM, manufacturer of the 'famous' Fritzbox ADSL2+/Draft-N Wifi router, released a beta software that adds Internet connectivity via 3G USB keys to their router software. I really like this box as it's crammed full of features such as a DECT base station, SIP capabilities, meaningful status reports, Wi-Fi interference monitor, DSL line visualization, etc., and now also 3G capabilities with an external 3G modem.
While it wouldn't work with a Huawei E160 3G USB stick, I managed to get it working with a somewhat older E220. The software is still quite an early beta and the GSM/UMTS configuration page in the router is not updated correctly once the connection is established as it remains in the "trying state". Nevertheless the connection is established and the main configuration screen properly shows the IP address and connectivity state. The throughput is the same as if the stick was connected directly to the PC.
Kind of an inverse 3G femto cell and great for traveling when more than one person or device needs Internet access or in areas without DSL coverage. For traveling, however, a somewhat smaller configuration, e.g. a 3G stick in combination with a D100 is probably preferable. For most users, such a setup is probably a lot more practical than the 3G Internet connection sharing via a PC, as I described a long time ago in this post.