The first is to add some new keyword-rich links to the
homepage -- holiday-focused, anchor text that the engines can pick up and will drive those last minute shoppers to your "great gifts and goodies."
Revising your meta descriptions
with seasonal search descriptions to snag shoppers is the second tip, but keep a record of which pages you've changed so that you can switch the meta data back after New Years.
Lastly, Spencer says that its not to late to leverage social media -- from crafting holiday-themed blog posts (like the top ten tips for last minute shoppers) to participating in reviews and ratings in communities like Yahoo Answers or Amazon's Askville.