Dreamhost recently started a new service called "Dreamhost PS" (announced at http://blog.dreamhost.com/2007/08/02/what-a-con/) . It is a cross between shared hosting and a VPS (Virtual Private Server). This seems like a great idea for people that need a little more power for their sites, but do not want to manage a full VPS and deal with everything "root" has to deal with.
The service allows you to scale from a guaranteed 150 MHz of CPU and 150 MB of RAM to a full 2300 MHz CPU and 2300 MB of RAM. These values are instantly adjustable (which will increase/decrease your monthly fee, of course) and also burstable. For example, if you are paying for the 150 CPU/150 RAM tier, you can burst up to 2300 MHz and 300 MB of RAM if they are free on the server. And if you max out at the 2300/2300 plan, you can burst up to 4 gigs of RAM.
I have signed up to pre-order this service, which is currently invite-only. Although I do like the idea of a VPS with full root access, 99% of the time, I just wish my shared hosting were a bit faster with some sort of guaranteed resources. The Dreamhost PS service will have a max of about 27 accounts per server, as opposed to hundreds on one of their normal shared servers. And, I will still have access to the storage and bandwidth I have accumulated with my time using Dreamhost. I am very much looking forward to when my account is activated on this service, and will follow up with my impressions.