Mass Node Update (e.g., disable comments for all nodes of a given content type) Is it possible to mass update nodes from, say, "Comments Read/Write" to "Comments Disabled" for all nodes of a certain content type?  

I changed the Content Type setting and that worked for all the other nodes types, except for a certain Node type that has given us problems in the past.

Thx
There's a module called Views Bulk Operations.

I never tried to do it, but I think you can write your own operations for this module pretty easily.