In OS X, you just assign Cmd or ctrl + mouse scroll for zooming in. This works anywhere, in any app.
Windows 7 also has a nice magnifier, and has some hotkeys:
Magnifier keyboard shortcuts
The following table contains keyboard shortcuts for working with Magnifier.
Windows logo key + Plus Sign or Minus Sign Zoom in or out Ctrl+Alt+Spacebar Preview the desktop in full-screen mode Ctrl+Alt+F Switch to full-screen mode Ctrl+Alt+L Switch to lens mode Ctrl+Alt+D Switch to docked mode Ctrl+Alt+I Invert colors Ctrl+Alt+arrow keys Pan in the direction of the arrow keys Ctrl+Alt+R Resize the lens Windows logo key + Esc Exit Magnifier
... but I want to use the mouse for zooming in and out like in OS X. Is that possible?