From time to time I read in those internet worlds certain applications that run on a pendrive, so that we can have our mail, bookmarks, Skype account, etc. always with us. The truth is that if we have access to a computer that is not ours and we want to ensure the privacy of our data is a good idea.
What happens is that users of Mac have an added advantage, and that is that we can take all our applications with us and all our files, no matter how big the portable disk or pendrive we have.
One of the great advantages of Mac and, by extension, Mac OS X over a PC with Windows is the standardisation of hardware. This makes it possible to boot any Mac with any disk installation, which is not the case with a PC . If you have a hard drive on a PC with Windows , and you take it with you to another PC of a different model (as long as the motherboard features are different) the chances of it not booting Windows are 99% (I leave one percent for the matches). However, if you have ever installed Mac OS X on an external drive, you will have been able to boot Mac from that external drive. Not only that, but if you plug that external disk into any other Mac , it will boot from that disk as a boot disk without any problem.
Since the 10.4.3 update of Mac OS X it is possible to boot any Mac from a USB disk . It has been possible to boot from a disk with a firewire interface for a long time. Since the installation requirements for Mac OS X are 3 gigabytes, if you have a portable drive with that capacity (obviously the bigger the better) you can take your Mac anywhere you want. From about 70 euros we can find pendrives with 4 Gb capacity, and external hard disks of about 80 Gb or more for the same price. We can also install Mac OS X on an iPod and boot from it.
I can soon think of two options: Install Mac OS X from scratch and migrate our user to the new disk using the Migration Assistant, or make an image of the disk and dump it to the external disk (obviously if the size of the destination disk allows it). By booting from that disk and installing the applications we want to carry with us, we already have a mobility that the users of Windows would like for themselves.