Hotlinking is posting your pictures on a board (like here on a DIS) that are stored in another place (like on ImageStation). There are very few 'free' services that allow hotlinking. This was one of the last.
I've been using a site called picturetrail http://www.picturetrail.com
for a couple of years now. I was a member of PhotoPoint until they folded. Although Picturetrail isn't as easy to use as PP, I have no complaints. I use it to post pictures here and also on my Ebay auctions. There is a yearly charge to use their site.
The pictures you see when you click the All My Kitties link at the bottom of my post are stored on Picturetrail.
www.worldzone.net - They have a FREE 50 meg account that you can upgrade for $12 a YEAR to allow hotlinking. Cheapest on the net that I've found. That and when you get around to actually using them to put up a small little family website you don't have all the ads dropped ontop of your site like geocities.