I have saved a lot of time by using the dual homing cpabilities of OS X - that is, its ability to connect to two networks at the same time. My home network uses a DSL connection and all the printers are wireless, but I prefer a wired cable modem connection when I am at my desk. OS X happily connects me to the internet at the faster cable modem speed, but allows me to print over the AirPort connection to my home network printers.
In my previous occupation, I was able to work on both the office network and through a wireless internet link; the OS just found what I needed on whatever network was required. No muss, no fuss, and no juggling of connections. I am set up to connect automatically to available networks, although AirPort does ask before joining any untrusted access points.
[robg adds: Though not exactly a hint in and of itself, not everyone may know that OS X can use two network connections at once, so I thought it worth publishing this...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060831154237448