With its help you can just select a number on a web page which you want to track, right-click on it and select “Add to Rival Alert” menu item – after that this number will be added to the Rival Alert, and its updates will be tracked every day, so that you would be able to keep an eye on the value’s changes:

The same can be done for FeedBurner counter images – just right-click on it and ”Add to Rival Alert” menu item.

Recently I have received an email from Mozilla:

If you are able to achieve Firefox 3 beta 3 compatibility by March 18th on addons.mozilla.org, you are eligible for a Mozilla Add-ons Developer T-shirt. If you have updated your add-on, and would like a shirt, please fill out the following form:

https://addons.mozilla.org/en-US/firefox/developers/tshirtrequest

Additionally, if your add-on is one of the top 50 most used add-ons by Firefox 3 users on the Firefox 3 release day, Mozilla will offer to sponsor (for an amount we will determine) a party for you and your friends. That is, Mozilla will chip in for you and your friends to celebrate your tools success! Mozilla will be in contact with the top add-ons shortly after the Firefox 3 release.

As for me, I have created a Get File Size plugin, and as soon as I did it, I have become eligible to fill a shipping form.

Here is a couple of links to help you on this way:

• http://developer.mozilla.org/en/docs/Firefox_3_for_developers
• https://addons.mozilla.org/en-US/firefox/blog/4

It is a good chance to make your cool plugin idea come true.

This simple plugin creates a HEAD request to the URL you clicked and alerts the size of the file – the value of ‘Content-Length’ header.