Well, I just can’t resist an OS upgrade, especially when it’s priced at £20.99 for all three of my Macs. There’s plenty of information around about what’s in Lion, and why you might, or might not want to install it, so I won’t go into any of that for the moment.

But for anyone who’s wondering about how they can use a Mac App Store download to install on multiple computers, or indeed to do a clean install rather than an upgrade, can I draw your attention to this useful article:

OSXDaily: Make a Bootable Mac OS X 10.7 Lion Installer from a USB Flash Drive

This explains how to open the installer package and copy the disk image file to a USB drive, which you can use to install on any of your Macs. Nicely done, and probably a better option than doing a download for each computer.

I’m starting by upgrading the MacBook Air, and I’ll let you know if anything breaks.

One thing you do want to note – if you use WideMail or Letterbox to change how Mail displays things, it might be a good idea to rest Mail to normal display before upgrading. It may not be necessary, but I’ve done it anyway, to avoid potential issues.