Show status outside the block, a little experiment...

I would like to do a little experiment with this module, and I need a slightly little help :)
Inside a weblog (a single user weblog), I would like to add this feature as a "last modified date", easily to change. Not inside a block, but inside the page.tpl.php
I know that there are some stuff out there to show last activity, but this would be for adding a customised, personal update. Maybe the person doesn´t want it to show all modifications that the site has suffered, but just post a custom date when he wants to.
And keep a record of that, so people could click somewhere and see all dates when the site´s owner has decided to tell the public "hey, I´ve update my site".

Is that possible?
Is there a code that usually is inside a block, that I should paste where I need this?

Thanks for your help and your thoughts about this!

Rosamunda