How much experience do you need in a language before you can put it on your resume? There is one language I'm in proficient in (Java) which I would definitely put on the resume but say I took I couple of semester courses in college which involved extensive programming in C or self-taught myself C# but have written no meaningful projects in it, can I put those languages on the resume without having the employer laugh at it or perceive it as resume inflation?
You can always list languages (as well as other skills) in tiers on a resume:

Proficient:    Java, Lisp
Familiar with: Perl, C++


As a guy looking at a resume, I will appreciate both the honesty and the effort; and when bringing you in the first question you usually get asked is to rate your individual language proficiency more precisely, orally or on paper.
