Running a web app in Grails vs Django
With Java hosting you don't need to do all the stupid tricks with apache, or nginx. Jetty itself can host everything you need, that's how the guys at www.mor.ph do it, and they find it to be pretty fast.
The memory usage that way is pretty minimal, I host mine on a 256MB Ubuntu server from RapidXen, so it's about $10/month.
I tried developing in Django, and while it runs all the scripts faster (like bootstrapping, or test cases) it's not as well-crafted in my oppinion
I'm currently in the planning stage for a web application and I find myself trying to decide on using Grails or Django.  From an operation perspective:

Which ecosystem is easier to maintain (migrations, backup, disaster recovery etc.)?  If using grails it'll probably be a typical tomcat + mysql on linux.  If django it'll be apache + mysql on linux.
Does django or grails have a better choice of cheap and flexible hosting?  Initially it'll probably be low bandwidth requirements.  I'm not sure about the exact specs required, but from what I've been reading it seems like django would require far less server resources (even 256MB server is ok) than grails.