Hey,
I have the international warranty from Pentax. I asked at their online chat and here's the info they gave me:
Randall S: To apply for International Warranty please provide the following information:
* Dated proof of purchase, which includes your name, address, and phone number
* Model name
* 7-digit Serial Number from the bottom of the camera
You may FAX this information to: Joe Virgil at: 303-728-0145
You may also mail this information to him at:
PENTAX Imaging Company
600 12th Street
Suite 300
Golden, CO 80401
Attn: Joe Virgil
or e-mail (with attachment) to:
joe.virgil@pentax.com
However, International Warranty applies to the first year of ownership, only, and may not be extended or renewed.
Just send the email with the info they ask and they'll mail you the international warranty. It took a couple of weeks to arrive for me (I live in Brazil), but it arrived just fine. Since the international warranty is only worth for an year I suggest you to this fast so you can get the repairs for you K5 using the warranty in time.
Oh yeah, this applies to lenses as well.
Hope this helps