You probably thought this was dead by now. Well I don't blame ya. I don't have much spare time at the moment.
I was thinking of making some buff icons/bars examples but I think the way Borderlands show active buffs is just plain boring but it's understandable, they only last for roughly 12 seconds max. They just show up, blink or glow (can't remember which) when they're about to wear off and then disappear.. Hell, that's no fun!
So I was looking at the next best thing. Skill cooldowns. The skill cooldown in Borderlands works this way. When you can use the skill it's fully visible. When it's on cooldown the complete icon goes transparent while it fills up from the bottom to the top with a darker color until it becomes usable and turns white again.
This is what I was tinkering with (yes this is a screenshot but it actually does work ingame
