Looking for something fun for the science lover on your list?
Dvice.com has a neat list of "11 Cheap Gifts Bound to Impress Science Geeks." From plushy microbes to Mars rocks, the list includes items for both adults and kids. My favorites are the Gallium samples and the Aerogel.
As described on dvice.com:
Gallium is a silvery metal with atomic number 31. It's used in semiconductors and LEDs, but the cool thing about it is its melting point, which is only about 85 degrees Fahrenheit. If you hold a solid gallium crystal in your hand, your body heat will cause it to slowly melt into a silvery metallic puddle. Pour it into a dish, and it freezes back into a solid.
This video from the Periodic Table of Videos shows how Gallium will melt in the hand, and features a cool experiment called "the beating heart" where the scientists use sulfuric acid to change the surface tension of a gallium sample. Sidenote: Video is also worth watching for the fantastic hair on Scientist #2.
I had my first experience with Aerogel when I was at the NASA Social for the Mars Curiosity landing at the Jet Propulsion Lab, and we got to see a sample of it. You can get your very own piece of the world's lowesty density solid over at ThinkGeek.com. This QUEST Lab piece gives the basics on the substance, including a little blowtorch demo showing off its insulation properties.
GeekSugar's gift suggestions trend more towards the scientific lifestyle, with suggestions ranging from Laboratory Beaker Mugs to the Hungry Scientist Handbook. I'm a girl who likes her jewelry, so I am partial to the DNA Ladder Earrings from NB Designs. The shop on Etsy has a whole bunch of science-themed pieces, including Petri Dish earrings and a Bacterium tie tac.
If you're looking for something a bit more experiential, Business Insider's suggested gift list features a night at the American Museum of Natural History. Bring your sleeping bag and a flashlight, and get ready to frolic after-hours at the Museum before settling down to slumber beneath the big blue whale.