Look up finger cots on Amazon or check your local drug store.
Apply healing salve and keep them on over night.
Here are the ones I have but there are many different brands. Reusable Rubber Finger Gloves(tm) for Durable and Versatile Finger Only Coverage
I'm always tempted by these, but as someone who (used to) wear gloves a lot as a lab scientist, it's really not good for your skin for it to be covered like that for long periods of time. Nurses, for example, who have to wear gloves most of the day are more prone to nasty infections around the nail area.
I like that, and how it covers the finger tip, thanks for the recommendation!
It's given me an idea - whether fingertip protectors might be worth trying e.g.
http://www.amazon.com/Gorilla-Tips-Fingertip-Protectors-Medium/dp/B0091C03YG
http://www.amazon.com/gp/product/B0002NYPGU/
etc.