Does Christianity have any dietary guidelines? Based solely on recollection from my childhood religious education, I understand that by Christian doctrine (regarding a vision/revelation Peter had), Jesus fulfilled the law and so the Jewish dietary laws (kosher) are not required to be followed anymore.  

How fully does this apply?  Do Christians get any "kudos" by eating kosher?  I understand that salvation would have nothing to do with it, but is it considered a "good work" anyway for whatever that's worth?  Do any other dietary suggestions/guidelines/laws apply to Christians?
Nope.  There are no restrictions.

We can even eat food sacrificed to idols.  This passage in 1 Corinthians talks about that.  The passage ends with the verse:


  1 Corinthians 8:8 (NIV)
  But food does not bring us near to God; we are no worse if we do not eat, and no better if we do.


Having said this, the author continues with:


  1 Corinthians 8:9-10 (NIV)
  Be careful, however, that the exercise of your rights does not become a stumbling block to the weak. For if someone with a weak conscience sees you, with all your knowledge, eating in an idol’s temple, won’t that person be emboldened to eat what is sacrificed to idols?


Essentially, we can eat anything that we can keep down that doesn't kill us.  However, this is providing that we do not cause others to sin.  (Though this is primarily in reference to food sacrificed to idols.)