For the past year I've seen so many modules out there, and am sure I've seen at least one that does this but haven't found them again.

Can someone point me in the right direction?

I am looking for something along the lines of a text/html module (or that can 'embedd' modules) where instead of going to different pages it just has tabs at the top to change what is displayed... hopefully without reloading the page each time, and being SEO friendly.

Thanks

I personally have used Mandeeps and it works lovely, the ajax enabled / disabled feature when used correctly can really assist with response times for those users wanting to tab around like blind monkeys. One thing I decided to do though was get the mandeeps subscription instead of buying the individual modules, cause you get much more bang for your buck, by combining their other moduels inside the tab module. Also once you get the hang of it skinning the tabs is pretty simple. So far I have not had any issues with mandeeps SEO capabilities and it follows DNN Search indexing so your DNN search will index your html/text modules. I only have brief experience with the others so I won't comment if they are good or bad, just wanted to say I have enjoyed the mandeeps product.

In regards of things to keep a look out for one key thing is tab security. It really helps to be able to display / protect content in the tabs based on user roles.