For Christmas, i knit the Wavy scarf for my brother-in-law. I used some Peruvian 100% wool for this - I only had 2 skeins and didn't know what to make with such a small amount. The scarf turned out a little shorter than the pattern said, but plenty long enough nonetheless. So, it seems like a perfect 'skeins leftover' project.
I hope the scarf will get some use - BIL is from Newcastle where people tend to walk around in T-shirts in the middle of winter, that's how hard they are! ;-)
I always add one of the wool labels to my hand made projects - this way the receipients will know what it is made of, and also whether it will need handwashing etc. This particular wool would fleece in the machine - it almost fleeced on the needles! So I am hoping SIL will read the label and heed the advice.