drummer boy

About a week ago I asked
this guy if he wanted to go
for coffee (don't know him
that well - first name basis,
we've talked a few times)
and he said: while smiling, "I'll think about it" (with his
hands behind his head) I have to admit the timing
was not that great because
we were in a busy hallway
and it was right before the
beginning of the final exam
period. The other detail I should
mention is that during this
last term I had a job where
he was a "student" of mine
(no - I am not a professor or
anything of the sort, and I was in no way involved with
any of his grades or marking
any of his work, and I'm not
super old or anything - I'm
also an undegrad, and this
job finished in late November) So I responded with
"Yeah...maybe after
exams.." (knowing that at
this time of the year finals are
like the main thing on
students' minds) And he said "Yeah I really
have to study but I'll see you
around" So I'm wondering when a
guy says "I'll think about it"
do they really mean NO (and
they just aren't brave
enough to actually say so)
OR is it possible that they actually want to "think about
it"? In this case I can understand
if he does want to *think
about it* given this unique
situation...but girls, in your
experience, when a guy says
this does it mean no? or guys, when you say this
does it mean no? Thanks in advance!