Unforgiven <jaapd4000@gmail.com> dixit:
>I came across this construction but couldn't find out what it meant.
>Any help?

If the full phrase is 言っとくけど, it means something like
"for your information" or "I'm telling you".

-- 
Jim Breen        http://www.csse.monash.edu.au/~jwb/
Clayton School of Information Technology,
Monash University, VIC 3800, Australia 
ジム・ブリーン@モナシュ大学