Getting to the top sponsored position in Adwords?

I've been running my adwords campaign for a few weeks now and am getting great results, decent CTRs (2-8%), and GREAT conversions. Now I want to step it up, and try to 'take over' the sponsored listings for my keywords by becoming one of the sponsors listed above the search results, rather than to the right.

How is this done? Is it the person with the biggest daily budget and the highest bid that gets there?

Also, I have been told that Google 'rewards' ads with high CTRs by giving lower CPCs or higher positions or something. How does this work?

Thanks,
Alan

I pressed the "Google AdWords Rep" at SEW over this topic:

http://forums.searchenginewatch.com/showthread.php?t=655

It's a complicated formula that includes several factors. As best as I understand it, there is a minimum CTR that must be achieved even for ads normally appearing at #1 in the sidebar - so it's not just a function of how much you are spending.

Thanks for the good link Bernard - I'd give you rep if I could!

I'm on the top for one of my keywords - its not one of my biggest, but still, on top is on top!