If you think you might like to go down the baby blanket trail, here's an idea for you: use a mixture of all the pastel colors in stripes. This makes a lovely blanket, which is gender-neutral!!
Another idea might be to knit some booties in neutral colors or I like the idea of the washcloths suggested by GG!
Most of all, choose a project you'll enjoy and have plenty of time for--but I bet you already knew that, huh?