There are about four apps on my iPad that I consider essential and Read It Later is one of those apps. If you use Chrome or Firefox you can download a Read It Later extension and anytime you come to a website you want to check out but not at that moment then click the little yellow arrow symbol and it sends that webpage to your account. Then you open the Read It Later app (you have to have WIFI or 3G for this part) and it downloads those pages to your iPad. Once it's downloaded you no longer need WIFI or 3G and you can still read those pages. It's like bookmarks made better.
Not only does it work in your browser but most Twitter clients on the iPad also support it. So if someone links to a page in Twitter once you click on that link it will ask you if you want to read it now or read it later. If you hit read it now it goes to the site just like it always does but if you hit read it later then it sends that page to your account. It works great and is one of those services I'm not sure what I would do without.
There are two versions of this app one is free and a pro version for $4.99. I'm not sure what the pro version does but I've used both and the free one works great. I went ahead and bought the pro version because I love the app and believe in supporting the developer if they make something I use. Pro Version or the free version it's something you should check out.