I kept noticing something that annoyed me which was the fans would often start whirring at full pelt just as I was going to sleep. The strange thing is that my MacBook (especially the new one) rarely makes a sound during the day. After a while they would spin down.

Last night the penny dropped – it’s the screen saver. The fancy, 3D hardware using screensaver. The moment I woke up the computer, the fan RRP started to reduce. So I promptly set my ‘Display Sleep’ time to 1min, and went to sleep soundly. Before, it was set to 15min – so it would eventually spin down (hence my previous observation as well).

Moral of the story: if you want your computer to stay quit right when you need it to be, use the ‘Display Sleep’ feature without screensavers (as attractive as they may be).

Re-ordering menu pages can be a real drag if each have a full set of icons – as when you move the icons around they bump off other icons. So I have an easy solution for you!

Your menu has 4 icons at the bottom which are always on screen, mostly likely thinks like the iPod and Phone apps. The easiest way to reshuffule is to temporarily move those 4 icons off to some unused screen – then use the space to move your apps wherever you like. When you’re done – simply put the original 4 back on and you’re done. :-)

Sharing the net however via ad-hoc wifi is easy. In System Preferences, go to “Sharing”, select Internet Sharing (don’t tick it yet), tick ‘Airport’ then tick ‘Internet Sharing’.

After you’re done – go into the Network Settings -> AirPort, and create a new network with a password (to stop those leechers). By default it is shared without a password which is dangerous (unless you’re in the desert or something). This new network should have the sharing on it if you did it right – but go back to the sharing tab and double check that it’s still enabled. Then on your iphone connect to your new ad-hoc network and enter the password.

Update: at least in Snow Leopard there is a button on the Internet Sharing settings named “AirPort Options” which allows you to setup the Wifi password in a better (more permanent) way than the one I described.

Update2: I have had some issues with sharing certain networks in Hotels – the iPhone can connect to my computer, but not the internet. One option is to install the proxy server Squid. This isn’t easy, and unless you are a developer with bash experiance I don’t recommend it (if you know what you are doing though it’s easy – just install the unix build tools, download squid, then ./configure, make and run it… default settings are fine – and just set the proxy IP in the iPhone to be that of your computer)

If you have no Wifi card (e.g. on a PC) then bad luck. If you’re on windows I’ll leave it up to you to figure out I’m sure there’s a way :-)

Call Divert – all calls – activate *21*(Number to divert to)#
Call Divert – all calls – to check *#21#
Call Divert – all calls – to cancel #21#

Call Divert – on busy – to activate *67*(Number to divert to)#
Call Divert – on busy – to check *#67#
Call Divert – on busy – to cancel #67#

Call Divert – on no reply – to activate *61*(Number to divert to)#
Call Divert – on no reply – to check *#61#
Call Divert – on no reply – to cancel #61#

source, and more codes