Getting a high-powered wireless router with some high-end features is a lot cheaper than most people think. In fact it doesn't cost any more than a regular router needed to connect to the Internet which allows the sharing of IP addresses between multiple clients. With the addition of DD-WRT, you can turn a cheap commodity router in to a high-end wireless router and switch. With the addition of a high-powered antenna located high up in the air which amplifies the send and receive capability of the wireless access point, anyone can set up their own wireless hotspot service with a massive coverage area.
Pictured to the left is the Buffalo WHR-HP-G54 router that sells for as little as $60 at all the local electronics stores like Circuit City, Best Buy, and Fry's or it can be ordered online. The WHR-G54 sells for as little as $50 and is virtually identical except for the fact that the WHR-HP-G54 has a receive side amplifier which helps the router hear faint laptops coming in on long-range connections. Both routers come with an RP-SMA antenna connector for external antennas which makes this router extremely flexible for wireless ISP and long-range bridging applications. The WHR-HP-G54 also comes with a wall mounting bracket so that you can mount the device up high.
This particular router can run DD-WRT using this specific upgrade procedure. DD-WRT can turn this cheap device in to an enterprise class product with enterprise features normally found in devices costing hundreds of dollars more. Things you often don't get on your consumer routers are features like VLAN (Virtual LAN) support on the switch, Enterprise Wireless LAN security support, QoS (prioritization), site-to-site VPN tunneling and VPN servers, Hotspot, and advanced routing features like OSPF and BGP. You can see a full gallery here with all the important features of DD-WRT.
[Update 10/17/2007 - Readers have commented that the OpenVPN function is very nice too. I'll also be looking at adding FreeRADIUS to this device and will follow up on it.]