There are several different ways documented of setting environment variables either system wide or per user, see this question.
Are there any options for setting environment variables on a per-application basis?
E.g. Is there a way to use something like ~/.MacOSX/environment.plist
or launchd.conf
but have some variables only inherited by specific apps?
The only way I can think of is to modify each applications Info.plist, but this involves changing an applications bundle which doesn't seem like a terribly good idea.