You have to be pretty careful if you elect to implement a “chat script” on a DreamHost shared server. Note the DreamHost TOS, which says in relevant part:
"MATERIAL PRODUCTS …
Servers are shared with other customers, and as such IRC-related activities or severely CPU intensive CGI scripts (e.g. chat scripts, proxy scripts, scripts which have bugs causing them to not close properly after being run) are not encouraged. … If your processes are adversely affecting server performance disproportionately DreamHost Web Hosting reserves the right to negotiate additional charges with the Customer and/or the discontinuation of the offending processes."[/quote]
(bolding is mine)
Many “chat scripts” out there are very CPU intensive, and can also contribute to an overloading of concurrent connections. It my opinion that, generally speaking, most “chat scripts” that your users will “like” could well be a problem on a shared server, particularly if the like the script enough to give it heavy use.