A Danae of All Trades

Gardasil, the vaccine against HPV strains 6 and 11 (which cause 90% of genital wart cases) and 16 and 18 (which cause 70% of cervical cancers), was approved last month in Canada for use in women ages nine to 26. In the US it was approved a month earlier for women ages 11 to 31. Edit: ignore that part of the survey below... apparently the thing I read that said this was confused. Also, keep in mind some doctors may be willing to administer for older women; it just might not be covered by your insurance.

The vaccine requires three doses over a six month period (day 0, month 2, and month 6), and costs $135 Canadian per dose, for a total cost of $405. In the US it is going for a total of $360 USD.

In July, the Public Health Agency of Canada's National Advisory Committee on Immunization (NACI) said it was reviewing scientific data and expected to make recommendations by the end of this year on whether provinces and territories should fund mass immunization programs.
-From Canada.com

In clinical trials Gardasil, manufactured by Merck, has been 100% effective in preventing infection with HPV strains 16 and 18, which together cause 70% of cervical cancer cases. The vaccine is also 99% effective in preventing HPV strains 6 and 11, which together with strains 16 and 18 cause about 90% of genital wart cases. Gardasil also protects against vaginal and vulvar cancers, two other gynecological cancers that also are linked to HPV, according to another study.
-From about.com

There are many other cancer-causing strains, but the ones that are most implicated aside from 16 and 18 are: 31, 33, and 35

[Poll #805885]