My GF took a job downtown Detroit....the first thing we did was get her a CCW permit and a handgun.
She decided, wisely I might add, on the SigSauer 380ACP. It's small enough to conceal in a small handbag, yet still has enough power to get the job done.
http://www.sigsauerpro.com/category/...p_Pistols.aspx
Sig's are a little pricey......but when you need it does the price really matter?