How many pictures will a 15 MB card hold on a 10 mega pixel camera?

Photos tend to average out at around 1mb per 3 megapixels. So on a 10 megapixel camera, you're looking at about 3.5 megabyte per picture. In short, you'll get around four at your camera's highest quality setting.

The short version: Get a bigger card. 1gb+ SD and CF cards are cheap enough that there's no reason to bother with tiny cards like this.