Lots of sites have gift certificates available online, including Sephora, Beauty Bar, Red Door spas, and Bliss's website and spas. Of course, if you're not observing the sabbath, there are no such restrictions, and you can always ask a friend to pick something up for you if you're really desperate. But regardless, the online option is one that's easy to give and easy to use, too.
So . . . it's Shabbat, and you still need to get a Hanukkah gift. Depending on whether you observe the day of rest or not, this could be a tricky one. The easiest thing is to give an online gift certificate. If you can manage to do it after there are three stars visible in the sky (and given how early it gets dark these days, you won't have to wait long), so much the better. That way, the site does the delivering and no one has to know that you ordered it same day.