I have a PS2, a Mac G4 running OSX and a Pentium Laptop running Windows 2000 and my ISP uses PPoE and dynamic IP addressing. At first glance, not an easy combination when thinking in terms of a home network. But then I read up on routers, and subsequently, wireless technologies and it's been a snap since then. I ended up going with the Linksys BEFW11s4 4 port 802.11b* router and the Linksys WET11 bridge. Both devices were super easy to setup and despite what the box and setup guide say...you CAN set the whole thing up from a Macintosh via your browser and system preferences.
Once up and running, you are able to set the WET11 up with any device using an Ethernet 10/100 port converting it to wireless. (In my case the PS2.) You can also connect up to 4 other devices via the router and a virtually unlimited number or other wireless, 802.11b compatible devices.. All will share your internet connection, even if its dynamically addressed from your ISP, and have access to printers, scanners and other devices sharing the network.
The system comes with a host of security options if you are concerned about hackers or outside hitchers riding your bandwith. I live in a very congested, tech savy part of San Francisco so wireless security is a huge issue. There are multiple levels of encryption, password protection, and filtering options to lock your system from all but the most determined hackers. You're never completely safe, but you can be confident with the options included here.
Performance wise, the system is above average. This will totally depend on where you live, what other 2.4ghz wireless devices you operate and the distance / walls separating the access point from the wireless connecting device. I have had 2 PS2s (one connected by cable the other wirelessly from another room about 50 feet away, playing SOCOM on 1.5mbps DSL) plus the Mac simaultaneously connected to the internet with little to no slow down. This is not to say the whole thing works flawlessly all the time. I have noticed that at times, especially during the day, lag can occur in online gaming with the WET11. I am assuming this is caused by outside traffic such as 2.4ghz phones and possibly other 802.11 devices. Again, the slowdown is very infrequent and negligable when it occurs. If this is a concern for you, you should look into 802.11a (still in development and about 3 times the price) devices that run on the 5.4ghz frequency which is less congested.
All in all, and if you've made it this far in my babbling, the combination of the Linksys 4 port router and the Linksys WET11 bridge should be perfect for those wanting expandability, compatability, reliablity and playability. Host a LAN party or head online solo from the comfort of your living room sofa, its all capable with this set up.
*(802.11b is the bottom rung of the wi-fi spectrum at the moment, which is the only thing that kept me from giving this 5 out of 5 stars.(11 mbps transfer rate compared the the 56mbps of .11a and .11g. This is only an issue when you transfer large amounts of data from one device to another or if you connect to the internet at T1 speeds) But it is also the most widely compatible and most cost effective of the three current technologies.)