Raspberry Pi: Extending the life of the SD card

Recently I posted about how I believe that the Raspberry Pi is the perfect small server. One question came up about the SD storage. SD cards are said to have a finite amount of writes that are possible, before they start to fail.

Is this an issue when using the Pi as a server? It could be, even though posts about SD card failures are scattered but not entirely conclusive. I started to look at ways to minimize the number of writes to the SD card, which in theory should help extend its life.