As we slowly get back into the swing of things after the holidays, let's take one last look at the online holiday shopping season. As Jupiter Media Metrix reported last Friday, during the last week before Christmas, the Jupiter Media Metrix Online Shopping Index, which aggregates Web visitors from both home and work to nearly 500 shopping sites and 19 subcategories, increased 57% versus the same week last year, climbing from 31.8 million to 49.9 million unique visitors. JMM's VP of Media Research Charles Buchwalter pointed out that in 1999 and 2000, the world was wondering if online …