According to
this article there are now officially '7 summits' on Mars!
They were named in honour of the 7 astronauts that were killed.
There may be plenty of chances to find more. After skirting Bonneville's rim, Spirit will head for the so-called Columbia Hills, about 1.5 miles to the east. Seven summits there are named for the seven astronauts who died in the space shuttle disaster in February 2003.
I guess Olympus Mons (27,000m) is not among them as it already had a name, so I think I won't bother climbing them
