I saw a Mouse, Where? There, it's a pair !!

[#1]

Apple's Magic Mouse is brilliant, it has all manner of swipes and gestures.
Most of which I don't use.
There is one extremely annoying factor though, it swipes any spreadsheets left & right depending on any slight twitch of the hand.
This is raised many times on Apple Forums...
Yes, I have installed MagicPrefs to get round this, but from sleep the iMacs take longer to wake up.
So I took the plunge, and ordered a couple of these...
HM8122  MOUSE, WIRELESS OPTICAL BLACK
3 Button wireless optical scroll mouse
http://cpc.farnell.com/unbranded/hm8122/mouse-wireless-optical-black/dp/CS2243561?ost=CS2243561
And only £3.30 each (Magic Mouses / Mice are around £45 each)
The iMacs' Bluetooth doesn't seem to recognise the mouse, but when I plugged the supplied mini dongle into the keyboard, it worked perfectly...
(Recommended to be Windows compatible only)
Pleased so far, I do a lot of Excel Spreadsheet / Word work, and especially Photo and Video editing, and now I don't have the annoying page shift.
I've tried other more expensive wireless mice in the past, none as good as this one...
I'll play around with the Bluetooth assistant to try & get it to work with the iMacs built in Bluetooth, but the supplied mini Dongle just sits in an unused USB port in the keyboard.
The battery life is supposed to be up to one year, Magic Mouse lasts 14 days ish.
And I've not had to change any mouse parameters, tracking & scrolling speed match the Magic Mouse

[#2]

It doesn't use Bluetooth - it will only work with a compatible receiver ( the dongle)

[#3]

Thanks, you have confirmed what I suspected.
At least the dongle works with Mac OSX
Though, System Report shows this...

[#4]

Yes, I use spreadsheets and photo editing a lot on iMac, mouse drives me crazy!
(Actually, I've switched to PC for spreadsheets now as Excel for Mac isn't same, or as good as PC version.)
Was just thinking of forking out for a corded mouse when I saw your post.
You said the dongle plugged into your keyboard.
My keyboard has nowhere to plug anything in. Would it go into the USB socket on mac itself?

[#5]

I didn't like the supplied Bluetooth keyboard with the new iMacs, so I use older white USB plugin ones, from previous iMacs.
This has a couple of USB ports on the rear.
Yes, it will work into any USB port, but then obviously you lose the use of that USB port for other purposes.
A USB "splitter" has given me problems in the past, with waking from Sleep.
With the new Mouse, wake from induced Sleep is instantaneous, I noticed that the wi-fi to router did not clear down as it normally does with the Apple Magic Mouse  !!
Unless the Sleep occurs due to Energy Saver setting, then wi-fi does clear.
For the sake of a few pounds, I would say try it, free postage from CPC until 7th June.
A reliable company, I have used them many times in the past, just be sure to check NO Catalogues etc.

When I initially plugged the dongle into the keyboard USB port, the iMac decided I had fitted a different keyboard, and proceeded to set one up.
I unplugged the dongle, plugged it into a normal USB port, the mouse worked immediately.
I then plugged it into the Keyboard USB port, and it was recognised immediately.
A thoroughly recommended "upgrade"
No problems at all so far, the left & right clicks are more positive, and require less pressure than the Magic Mouse.
One last thought, have you tried magicprefs ?
http://magicprefs.com/
That worked for me with the Magic Mouse, but waking up from sleep takes forever ! (30 seconds ish)

[#6]

Thanks for that, useful info 
I'm now wondering whether I want to pay extra for a corded mouse or get this cpc one.
One of my other gripes is batteries. Can't see any real advantage on a desktop mouse? Esp if using Photoshop which is pretty mouse intensive.
I've seen little, almost round, corded mice in the Apple store which they use for display machines. I'd quite like one of them.
But, if this Windows mouse works on a mac, maybe other corded ones will as well? I'd always assumed they would not.
Not worried about USB slots. Only used for one backup drive, that's it.
Not sure if magicprefs has an older version. Need to check that out. I'm still on SnowLeopard!!!