This method is able to send common informations inside SWF too, using a "sentinel" file or directly full SWF to load.
Since Internet Explorer 6 add a new ActiveX control that requires at least one click before user can use SWF content many developers wrote different libraries to fix this problem, present on IE 7, Opera 9 and probably other browsers.
These libraries are good enough to solve "activation click" problem but these often offer more features we (at least me) need.
This is why I've just uploaded my last tiny library to solve this problem, compatible with IE6, 7, Opera 9, FireFox 1.5+, Safari 2+ and many other browsers.
Its size? Actually exactly
How to use them? Just include them externally using a script tag.
Crazy Source (self packed)