if your on cable it wont change often enough for it to really matter, it will generally change when your computer resets its connection, and you can view when your computer is scheduled to refresh its IP through ipconfig, if Im not mistaken. Usually your computer will change IPs when your computer crashes or restarts which happens to me more often than it changing IPs naturally.
Ive had lots of luck hosting internet radio over cable, and that requires a stable IP, I just had to update the link every few weeks.
Hope that helps
oh and btw, your not the only person who cant search, none of us can... read
this thread for more info.