HLStats provides some signature image of your current rank.
To use this feature ask the webmaster of the HLStats installation if this is possible.

If so you can query your stats as follows:

http://www.domain.tld/hlstats/sig.php?playerId=1234

This will return an image with the default style:

Size: 400x100 with transparent background. Default is a png file.

Here is the list of the possible query options:

sig.php?playerId=1234&style=red
This will get the player information with a differnt background:
[green(default)|black|multi|red|blue|css_nitro]