I sent a client to a wrong URL to preview some work today, luckily the server had some sort apache voodoo enabled, and automagically redirected the client to the correct URL. It just worked, it was transparent.
“Contingency Design” is necessarily a difficult thing to sell (“we’ll make your application user-friendly, even when it goes wrong!”). The tricks and techniques to get people “back on track” need be pointed at and applauded. That’s what half of Design Not Found. The best and worst of contingency design does:
Contingency design - a field pioneered by 37signals - is design for when things go wrong (error messages, no search results found, missing pages, bad form entries, etc.).
I like the site because the good examples are worth pilfering ;-) and the “bad” examples have a “Simple solutions to this problem” section that demonstrates the Zen Like Power Of Common Sense.