Instapaper lets you bookmark online content through a handy little bookmarklet that sits in your browser. Then you can log on to their website later or use their iPhone App to read the full articles in one place.
Their connection with the Kindle is simple — they have a service by which your recent articles are emailed to your Kindle or Kindle DX. You get charged $0.15 by Amazon for each email but in the end it is worth it to be able to read it on your favorite e-text reading device.
But there is a problem with this service, the emails do not reach the Kindle users every time they are sent. This is in all likelihood a technical problem between the Instapaper’s service and Amazon but it is taking its time getting fixed. So the Instapaper developer thought up an alternative solution.
Instapaper now allows you to download your 10 most recent articles to a .mobi file that can be transferred to your Kindle. You cannot go more than 10 articles per file for now but you can probably save multiple such files. Syncing is via USB, so it is not completely hassle free but it has three distinct advantages for now.
One is that you get to use this service for free. You will not be paying for the emails that Amazon relays from Instapaper to your Kindle. The second advantage is that you are guaranteed that the sync feature will work all the time. The third is that it works for International users as well. The email feature was only for US users. It is still in beta, so you might run into problems but those who use the Kindle with Instapaper know that it is a fantastic service to have. It adds to our already great Kindle experience.