Once you take a screenshot on Halo 3 they automatically upload to Bungie.net in anytime between immediatly and 48 hours. Btw, why so many questions marks?
(Directions Stolen from Wakko) To Embed Pictures: 1. Save the picture onto your computer by right clicking it and pressing save as... 2. Go to: http://imageshack.us/. 3. Once there click Browse. 4. Search for the saved picture. It'll be where ever you saved it. 5. Double click the picture to select it. 6. Press "host it!". 7. Scroll down once it bring you to the next screen. 8. Copy everything in the "Hotlink for forums (1)" box. 9. Paste it in your post.