Evernote allows you to "note to self" just about anything. Use it to collect interesting websites, photos and more from your computer and you'll have access to all your notes while on the go. Conversely, anything interesting you come across while out in the world can be noted with the Evernote app and accessed later from your home computer, tablet or any of your other connected devices.
Download links: Android | iPhone
See also: Springpad, Remember The Milk, Toodledo