So I'm stuck with really sub par internet conditions. I pay for wifi access that only allows one device on at a time. The bandwidth is a max of 3g down. It is a super pain in the ass having to log out of each device every time I want to use another device. Is there a way to have my laptop share connection to my dd-wrt router and make it only look like there's one device on?
Yeah, basically you need to run NAT on whatever device is connecting to the WiFi and then configure that device as the gateway for other devices on your network.
What kind of connection is it? It is WiFi or some kind of cellular connection?