There are several ways to do this, but here is the easiest...
1. First, edit the image on your computer to get the image size down and save it as a jpg with medium/high compression to get the file size down to 50-100kb max.
2. Log into the photo gallery at kingsnake.com (there are links each kingsnake page). Log in with your user name (the one you use to post) and click the upload photos link. Give the photo a useful name so that you can remember which one it is.
3. Get back in to the forum you wish to post in, and when you post, there is a "Select Image from Photo Gallery" box below the message box. Click the arrow and choose you photo. Click Preview Message and check it out. Realize that in the final post, the pic will be centered and at the top of your post, not on the bottom.
Submit your post and voilà!

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Chris Harrison