Check out Slingshot- basically CloudApp for Dropbox. It sits in your menu-bar. When you take a screenshot, it uploads it to your DropBox public folder and puts

Check out Slingshot- basically CloudApp for Dropbox. It sits in your menu-bar. When you take a screenshot, it uploads it to your DropBox public folder and puts the link in your clipboard. Super easy and no subscription (I think it costs like 3 bucks in the App Store)