Sometimes science-related gifts are obvious, like the traditional chemistry set (like these, found on Amazon), but others are a bit more ingenious.
Etsy, the online source for all things quirky and vintage or handmade, offers up a few ideas. For the budding biologist, there is this very introductory cloth molecular genetics book as well as this onesie that that identifies the wearer as possessing an X and a Y chromosome. (Also available in XX.)
And for those looking to furnish or spruce up a home, these DNA-patterned pillows may fit the bill. But if not, there are art pieces that may do this trick like this mixed-media karyotype by Louise Philbrick or these DNA portraits from Louise Fellman.
For the fashionistas, there is this DNA-styled dress as well as these stockings with a helix pattern on the calf. Added to that are this DNA necklace or this graduated cylinder necklace as well as this mitosis scarf (HT: Graham Coop). In addition, James Hadfield from Cancer Research UK is auctioning off Ion Torrent cufflinks on eBay to raise money for his organization, so it's fashionable and for a good cause.
Finally, don't forget these stickers for the Drosophila-lovers on your list.