I just got an Apple iPod. Cool !!!!!!!

I have had a pair of Sony MDR V6 headphones for years. I like them
pretty good, but would like to know what models I would have to go **up**
to in order to realize an improvement in the sound.

I have seen many references to the Sony 7506 (I think that is the number).
Would this model be an improvement over what I now have?

What other headphones should I consider, say in the $100-150 range?


OR, do I already have the best sound in this price range with my old Sony
MDR V6 ???

I will appreciate any comments and advice !!

--James--