This site is running on Webfaction. We also frequently test Sputnik installations on Dreamhost. And if you sign up after clicking on one of those two links, we save on hosting.
Note that your host does not need to support Lua. If you want to install Sputnik on Dreamhost or another shared hosting service, just follow the installation instructions described on the Installation page. The only change you would need to do after that is put your sputnik.cgi file in the right place, and set the BASE_URL parameter to the right value.
For instance, on webfaction, I currently have:
- sputnik.cgi is in "~/webapps/static/cgi/sputnik.cgi"
- BASE_URL is set to "/cgi/sputnik.cgi"
On Dreamhost:
- sputnik.cgi is in "~/takhteyev.org/sputnik.cgi"
- BASE_URL is set to "/sputnik.cgi"
Note also that depending on the specific server's policy, you may need to set different permissions on the sputnik.cgi file and the directory where this file goes. (Doing "chmod 0755" on the file and the directory will probably give you the highest likelihood of success.)