Save this as a compiled script and put it in ~/Library/iTunes/Scripts/ and it will appear in your Script menu in iTunes (or call it outside of iTunes if you prefer).
tell application "iTunes"
set currart to artist of current track
set curralb to album of current track
tell application "Finder"
open location "http://www.walmart.com/catalog/search-ng.gsp?search_constraint=4104&search_que
ry=" & currart & " " & curralb