If you're interested in high-availability you typically want to use some kind of load-balancer, to divide traffic between a pool of machines. A simpler approach can be to have a pair of hosts each of which is prepared to take over a single virtual IP address - this is what ucarp allows you to do.
This is a short HOWTO on setting up a backported Postgresql 9.1 database with streaming replication on Debian Squeeze.
sudo is an essential tool in an environment where there are multiple server and system administrators. By default sudo will log to syslog, and it is very straight-forward to isolate the logging to a local file which can be useful.
Newer GRUBs can handle a /boot partition which is btrfs, so you need not have a separate /boot partition formatted as ext3/4.
Western Digital's My Book Live runs on Debian Lenny. It is a pretty nice NAS missing one critical feature for which many people ask on-line: The ability to sit behind a home LAN router and update a dynamic DNS entry as many routers can do.