Mortgage Question

I bought a house in July 2004 for 195K. Was able to put 20% down.
Original Loan Amount is 156K. Pricipal Balance is now 155K. Interest
Rate is fixed @ 5.75 percent. Our house has been apraised for 240K
from 2 recent independant appraisers. (We did get a good deal, because
we bought the house right before it went to sheriff sale.)

Should I continue to just make monthly payments? What options do I
have? I have heard that maybe I should remortgage the house (or have
the house re-appraised by the mortgage company)  because of the equity
in the house or because the house is worth more than what we purchased
it for.

I am bit lost in this situation. An acceptable answer will provide me
with a few if any options that I have with this situation. From what I
understand and from what people have told me, I might be able to put
myself in a more favorable financial position????

Mortgage is not my forte. ;)