xkcd

Today's comic from xkcd - a webcomic of romance, sarcasm, math, and language. Which you should probably read. If you don't already.

Plus they have a very cool use policy:

Note: You are welcome to reprint occasional comics pretty much anywhere (presentations, papers, blogs with ads, etc). If you're not outright merchandizing, you're probably fine. Just be sure to attribute the comic to xkcd.com.

Hand sanitizers are actually very interesting because there is a very active debate about whether their use leads to antibiotic resistance. They themselves are not antibiotics and have different modes of action but the vast majority contain a substance known as Triclosan. There is a pretty active debate about Triclosan. Stuart Levy's article Antibacterial household products: cause for concern is a good starting place if you are interested in this topic.

Scientists are concerned that the antibacterial agents will select bacteria resistant to them and cross-resistant to antibiotics. Moreover, if they alter a person's microflora, they may negatively affect the normal maturation of the T helper cell response of the immune system to commensal flora antigens; this change could lead to a greater chance of allergies in children. As with antibiotics, prudent use of these products is urged.

Hand sanitizers can be great if you aren't able to wash your hands but should not be used in place of hand washing. Use of compounds like Triclosan in other products is rarely warranted.