Assuming 2nd domain can reach the SQL Server then yes.
They would be seperate DNN installations, you should use seperate object qualifiers i.e. dnn1_ and dnn2_

You would need to test this though (and backup you sites first). I would be very concerned indeed about the speed in this configuration, i.e. SQL data over the internet could be pretty slow, it just depend how fast you can connect and transfer data. If both domains are with the same hosting provider then fine, but check their terms and conditions.

If you wish to share content between domains you would probably be looking at third party solutions, I would thus recommend you just stick with just one DNN instance and create just create more portals for each domain on that one instance (you would probably still need third party applications), but be concerned though about the memory you have available in you application pool. Check out RSS and web services.

Good luck...

I tried it, but I failed... to complicated for me. I wanted to keep the two separate hosting accounts because there is more than just one site on it.

But now I will move them all together.

Thanks for the info.