Chrome Extensions

I'm starting the development of chrome extensions, i have read few tutorials but i still have few questions, like;

1) How to get the text of the page Like i want to in skype or google talk extesnion the number on any webpage are converted to PHONE LINK how can i do this?

2) How to perform authentication using the plugin like开发者_运维百科 the google plus (gmail) checker, I want to do this for another website not gmail, i want to do this for me custom website.

Thanks

1) There are a number of ways to ways to find text on pages. Here is an example with jQuery.

2) Google has a tutorial for using OAuth from an extension. This should work with most OAuth providers. You can also use cookies or Basic Auth if you want something simpler.