my experience designing a logo..that will be a different designing a logo..that divided into two different ways..
firstly..for offline.agreed with mysticmind...the logo should work in black and white also and also no need to put heavy gradient on that logo..It won't work for print design..
secondly for online..for online matters, not every client or contest holder want the logo to be print..so now people always get crazy with 2.0 design style logo..it comes with heavy gradient and always using specific color for specific categories of concept..
this is my experience at DP and also at sitepoint design contest..
