Is it appropriate to include declined post doc offers on your CV?
I've seen a few cases of people in my field (linguistics) turning down competitive funding offers and listing them in CVs with "(declined)". Some of these happen to be tied to postdoctoral positions, especially ones offered by governments and/or prestigious granting agencies.

And depending on field/location, it might be possible to list job talks as 'invited talks' for particular departments.

Beyond that, I think referring to job offers you have refused is inappropriate and likely to look only like showing off.