I'm the person that probably started that thread. I've talked to the City Forester for Baltimore, who had some questions related to liability issues. I referred him to someone on this board who'd worked out these issues for other cities before. I'll drop him a note this week and make sure that they're still making progress.
The City Forester offered us the site where the ISA 2000 jamboree was held, Druid Hill park. This is about 3 miles up the road from the Convention Center, but easy to find, with good public transportation access. I'm also exploring sites within walking distance of the Convention Center. I don't think there's any within a couple of blocks, but there is Federal Hill, maybe 5-6 blocks away, that's a beautiful location on a pretty good size hill overlooking the Inner Harbor.
Let me know if you have any suggestions or questions.
-Kevin