Wordpress plugin, text ads based on post??

Is there a plugin where you can create a bunch of text ads, and then on the 'Add New Post' page, have two drop-down boxes where you can select which text ads you want to show up, one text ad showing up before the article, and one after the article?

no there is not unfortunately but why don't you use bloger or blog spot

Try quick Adsense ... It gives you short code while posting new post which you can use above below in between anywhere in the post

you can try admanager, but you need to put some php code on theme

Found one.

http://wordpress.org/extend/plugins/seo-automatic-links/ - SEO Smart Links

then I did a tiny bit of changing in the script

//Original code
//$replace="<a title=\"$1\" href=\"$url\">$1</a>";

changed to

$replace="$url";

and for Custom Keywords, do it this way...

myad101, <center><H1><A HREF=http://www.domain.com>Text ad Link</a></H1></center>

Place myad101 in the post content and you get the text link.