This can work in some situations, but you should also be careful of over-using these accents. If you look at a site like amazon.com, for example, you'll see that they use solid colors and "flat" text more than gradients and drop shadows.
Pages also need white space to help organize content and avoid crowding.
So, if you go with gradients or drop-shadows (or effects in that realm) know that you're doing so at the expensive of a resource that adds readability and overall usability.
That's not an argument against using these things, just an argument against gratuitous application. (Consider that Amazon, for example, manages to get a good deal of content on their pages while still being fairly easy to grok.)