Auto resize mobile site question

Hi guys:

I created a mobile site for our company and I’m pleased with it because it suits our purpose, however, I am having a difficult time figuring out one thing…

How do certain mobile sites like cnn and espn auto-zoom, or shall I say resize, to fit the mobile devices screen. For example: When I bring up a website on my ipod or cellphone sometimes I have to double-tap the screen to zoom in on the content and it will then auto-size the content to fit my screen. But it seems cnn and espn automatically do this on the loading of the page. I’ve checked their code and I don’t see anything specific…

Here’s my mobile website:

http://www.seifmedgraphics.com/mobile/

Here’s CNN’s mobile site and ESPN’s mobile site:

http://m.cnn.com/

Is this a javascript command? Thanks in advance for any help. I truly appreciate it!

Sincerely,

Greg