Webshots, Photobucket, and others... most will work.
But, you could post it in your Pipesmagazine.com Album then open the photo... Right click on the photo and select Copy Image Address.
Then open the string where you want to post it.. e.g. this one :D then click on the IMG button above the Reply Box paste the Image Address there and click Send.
Poof! Photo in the string.