Hey,
at the moment Threadless only offers one method for international shipping and that is the DHL Globalmail Standard International Shipping Parcel.
* Standard International Shipping (9 to 36 business days)
Now - it does NOT have tracking capilities and does usually take a few weaks (not to mention it gets often lost..).
Well - but they have another better quality service which threadless really should offer in my opinion:
* Expedited International Shipping (6 to 22 business days)
The cost does increase for like 10-15% (if im correctly).
But it is really FAST (my last items took only 4 days from the usa to germany) AND it does have TRACKING capilities (which i believe is nescessary for good international order-support).