I had one when I worked in retail b/c it was required. Why, I don't know since they often went through our bags before we left anyway.
Sometimes cosmetic companies give them as part of a GWP during summer months. That's actually how I got mine - as part of the gratis from the line I worked for. I'm with Stophle though...I'd be really uncomfortable using one as a daily handbag. But, hope you find something you're happy with!