DD-WRT, WRT54G2 and YOU!
It looks like my post on DD-WRT and the WRT54G2 is pretty popular with the readers, so I'm going to clear up a few of the questions that have been brought up. First and foremost, the WRT54G2 is going to run a very limited version of DD-WRT. If you want to run a full blown version of DD-WRT, you're going to have to get your hands on a WRT54GL or one of the other routers that is designed to run full open source firmware. I have used these and let me tell you, they work great. I've set up Chillispots all over the place using those, as well as creating a really nice mesh network for a large office. So, the answer to one question is yes, you can create a wireless mesh network with DD-WRT. Even the smallest install supports linking routers and mBSSID just like the much more expensive Aironet products from Cisco.
Now, I have a confession to make. I bricked my WRT54G2. I wasn't paying attention and tried to upgrade to a newer version of the firmware when actually it was an older version. I'm the guy that wrote the how-to on upgrading this router and I screwed it up. Awesome! You should be fine as long as you follow the directions in my previous post on this. Currently I'm running a WRT54G v6 and a WRT310N at the house. The 54G is running in G only mode, the 310N is running in N only mode. The reason I'm doing this is because when you run a dual band router in mixed mode, it's going to suck. I was only connecting to the 310N with my N adapter at 65 Mbps. Once I added the WRT54G in AP mode and G only and moved the 310N to N only mode, that jumped to over 130 Mbps.
If there are any more questions about this, please don't hesitate to post them. I'll be more than happy to answer your questions.
-Greg