I dont understand all those blogs are on technorati but none of them have tags displayed on their blog...i guess i'm missing something here
Just because you don't see them doesn't mean they are not there. For technorati to see the tags, the tags must exist in the post. However, that doesn't mean you can see them on your screen too.
Consider this bit of html:
<a href="http:/example.com/tag/blah" rel="tag"></a>
That will be seen as a tag by technorati or any other tag system, but it won't display anything on the screen, because the link is empty. There's nothing for it to display.
There are other ways to do it. One easy way is to include the tags on the page but then wrap them in a hidden span element, like this:
<span style="display:none"> Anything in here will never show on the page, though it's there anyway </span>
If you use UltimateTagWarrior, it has an option for "invisiblecommalist" which uses this hidden span method to put your tags into the page without showing them.
If you really want tags, get a tags plugin. UTW is great, I highly recommend it.