I've been hosting a couple of domains using Apache / PHP and
AOLServer / OpenACS 3 with Hub for the last couple of months.
I've found them to be very, very helpful, and quick to respond to
email requests. They will also install almost any software you
request.
Marc Fournier (who I believe is / was one of the Postgresql
developers) sent out an email which I partially quote below.
<quote>
This morning, user support at Rackspace reported a problem
with accessing our server based on their monitoring software.
After investigating, it was determined that the problem was that
the operating system had run out of required buffers for the
network interface, which required a reboot.
In order to avoid this happening again in the future, we raised
the number of buffers available, which we hope will prevent this
from happening in the future.
</quote>
I would definitely recommend them as a great host for budget
conscious OpenACS (or other) developers. I've asked why they
haven't advertised a bit more on openacs.org, and been given
the response "we don't like to blow our own trumpets" (or words
to that effect). Helpful, modest, and considerate.