Some big-box hardware stores, I have seen them in both Lowe's and Home Depot, carry nitrile gloves in packages of 20 gloves under the Wells Lamont label.

Also many drugstores carry boxes of 100 nitrile gloves for about $6 last I looked. Unlike latex gloves, which degrade more rapidly once the package is opened, the nitrile gloves can be repackaged in zip-lock baggies and keep well. This allows you to keep a small stash in lots of places.