ok well this isnt reeeeally a hack or secret or whatever but I'll post it anyway.
if you've ever had any problems with your wrist straps or just want some new ones then you should go here
http://wii.nintendo.co.uk/6315.html because Nintendo are giving away free thicker wrist straps for everyone who has a wii. there is also a comparison on the page which can show you which ones you have. I'm not saying that the originals aren't safe but these are better.
now remote jackets. these are basically crash helmets for your wii remotes and if it flies out of your hand then these will protect (to the best they can, they're not indestructible) your wii remote and whatever it hit. if you want these then go here
http://wii.nintendo.co.uk/22686.html
you actually need a wii before you can get them because you need to enter your serial number.