I don't see how posting an image from the postimage.org link that BigHat provided in his OP could possibly be any simpler than it is.
There's even a direct hot-link for forums.....second option from the bottom, if I recall correctly. Two clicks and it shows up here with no extra crap to deal with.............an d like he says, IT'S FREEEE! 
I belong to two other forum (WineMakingTalk, and Backyard Chickens) and both of those site let you upload images directly from you HD, or camera. Click on the 'add file' icon, browse your picture files on your computer, and select. Bing, bang, done... I think that's what XJ is talking about.
I checked out postimage.org and didn't like some of their policies. Main critics cite their very limited storage space for non-paying members. I finally got some of my questions on Imgur about Albums and I like that site a lot.