The Gadget: Caps4Stix rubber thumbstick covers for Xbox 360 and PS3. They're meant to add more grip for better precision and control.
The Price: About $2 per pair.
The Verdict: Pretty good! I usually hate this rubbery add-on stuff that fattens up a sleekly designed gadget, but I have to admit, playing both the PS3 and Xbox 360 felt better with the caps than without. The texture isn't just more sticky, it also has a few nubs that support your thumbs as they push the sticks farther off center. (In picture above, left stick is capped, right is normal.) And the covers don't add too much bulk, either, even though the first few minutes of testing were definitely a strange sensation.
So do I play better with the Caps4Stix? No clue. But they aren't just a solution to a problem that doesn't exist. They are more like a subtle improvement on something that you'd never have realized was broken. Like a fix to a carbon monoxide leak if carbon monoxide just burned off a few brain cells instead of killing you.
Now if only you could buy them in a color other than black to match the 360 controller... [Caps4Stix]