As of May 4, you will be able to send RTF files to your Kindle email address for convenient wireless delivery.
This is added to the DOC, HTML, JPEG, GIF, PNG, BMP, TXT, AZW, MOBI, and PRC, that your Kindle2 already support.
Also, in addition to sending experimental PDF, you will be able to send DOCX files for conversion.
Some complex PDF and DOCX files might not format correctly on your Kindle.
The fee for sending the files will now be based on the size of your file.
The new rate for this Personal Document Service (via Whispernet) is will be $0.15 per megabyte rounded up to the next whole megabyte.
Downloading your personal for free is still an option if you are not in a wireless area, or you simply do not want to pay the fee.
To get the free file transfer, send attachments to “name”@free.kindle.com to be converted.
These documents will be e-mailed to your computer at the e-mail address associated with your Amazon.com account login.
You can then transfer it to your Kindle over USB for free.
For more information on this you can visit Transfering Documents and File to Kindle 2 at the Amazon website.