Keyboard Shortcuts for Photoshop's Layers Palette.
It's a sign you know your way around Photoshop when you've mastered the keyboard shortcuts for the Layers palette. Here is a quick reminder: Combine the bracket keys [ or ] with Option/ALT to select the layer above or below; Use Command/Control to move your selected layer up and down.
Adobe has the full list of layer palette shortcuts on their Help Resource Center:
Source: This tip inspired by two workshops on CS3 Layers this week at CreativeTechs. This Wednesday morning, Jasson Hoppe presents his popular workshop on CS3 Layers: InDesign, Illustrator, Acrobat, Etc. followed by Photoshop CS3: Mastering Layers on Thursday.