You don't need a bridge. All you need is a router, which will include a firewall and 4 port switch. If you want the imac G3 to have wireless access you need a wireless router, and a wireless NIC for the imac G3. If you can't install a wireless NIC in the imac G3 you could use two Buffalo WHR-G54S routers and use the bridge feature instead.
I highly recommend the Buffalo WHR-G54S router. It has excellent performance and stability. It has a bridge feature which I, like most people, don't use.
You can install a router and everything will work using the default settings; but the minimum you should do with a wireless network is enable encryption. The Buffalo WHR-G54S can use anything from 64 bit WEP, the least secure but adequate for most people; to WPA with EAS encryption, the most secure.

Pete wrote:
>
> Hi
>
> I'm looking to set up a wireless network and I'm a bit lost.
>
> My PC has a 2MB connection to Virgin Media(Telewest) via a DSL Surfboard
> SB3100 cable modem. I also have an imac G3 400mhz with an ethernet socket
> that wants to share the internet access.
>
> I was told the best thing would be to get a wireless router and plug it into
> my existing cable modem, then connect the router via cable to my PC. Then
> get a wireless ethernet bridge for the iMac to connect to the wireless
> router.
>
> The thing is that from a quick look around, wireless ethernet bridges seem
> to be quite expsensive at the moment and it seems I can get a "Buffalo
> Airstation G54 Wireless Cable/DSL Smart Router " for the same price if not
> less. So i thought why not get 2 of them, connect one to the iMac, one to
> the PC and let them chat. The marketing information on the Buffalo Router
> states "In addition to fast wireless performance, WHR-G54S features a
> built-in external switch between wireless router and wireless bridge access
> point."
>
> Would someone please confirm that this is saying what I think it is saying?
> Does this mean I could buy 2 of these and connected one to the existing
> cable modem as a wireless router and connected the other one to the iMac but
> flick a switch on trhe imac router so that it acts as a wireless ethernet
> bridge? I am assuming the ethernet bridge/router would work without me
> having to install or configure anything on the iMac.
>
> I Hope what I have said makes sense as I'm not a network expert
>
> Would someone also confirm that I can physicaly connect my pc to the router
> rather than have a wirelesss connection?
>
> Thanks
>
> Pete
>
> Here's the marketing blurb:
>
> The Buffalo AirStation G54 Wireless Cable/DSL Smart Router combines the 125
> High Speed Mode wireless performance with Buffalo's AirStation One-Touch
> Secure System (AOSS).
>
> This router increases "real world" wireless performance up to 35% compared
> to a standard 802.11g Router and automatically detects and configures your
> Cable or DSL Internet connection. Security features include WPA, WEP,
> Privacy Separator, Intrusion Detector, and SPI firewall.
>
> In addition to fast wireless performance, WHR-G54S features a built-in
> external switch between wireless router and wireless bridge access point.
> The combination of speed, security, and push-button setup of wireless
> connections and Internet, makes the Buffalo AirStation G54 Wireless
> Cable/DSL Smart Router the ideal choice for your wireless network.

--
Mike Walsh
West Palm Beach, Florida, U.S.A.