What to use on a 32GB flash drive?

[theMastermind]

So I've recently bought a 32 GB flash drive, I'm planning on using it for installing OS, booting live versions etc.
I've used YUMI to add bootable files to it, and what I have on it so far is:
- Windows 7 32bit/64bit installation
- Windows XP installation (Yes, I know  there's still some older people around me used to it and not wanting any changes  )
- Slitaz 4.0 lightweight linux OS (I'm open to alternatives, it was just my first, let's say random choice)
- Backtrack 5 (it seems now that Kali is the new/better version, any thoughts or experiences on that?)
- Hiren's Boot CD

YUMI adds some Windows 7 files (such as setup.exe) into root, a bit annoying, but I've put all of these folders and files into hidden state, just so it doesn't get messed with if I borrow the flash drive to someone else.
So, what I'm asking is what else should I add to it? I'd be glad to hear what Portable Apps software to add to it as well, along with any bootable stuff recommendations!

And while I'm at it, recommend any free file backup alternatives, since I'll add some space on it for a TrueCrypt (7.1a) container to keep some files safe as they can be.
Thanks!

[MilesAhead]

If any customers have newer systems with W8 you may want to set up another stick for UEFI boot(you can turn off secure boot on the customer's machine temporarily) and GPT.  I've just been playing around with bootable USB and even W7 Pro x64 will not boot from the stick when everything is properly formatted.  It gets to the Starting Windows and hangs.

You may want to put some W8 utilities or a UEFI bootable Linux on the stick to service those on W8 and later,

I haven't played around with changing the setting to Legacy Boot because I want VHDs that will boot from the boot manager screen on startup.

[theMastermind]

If any customers have newer systems with W8 you may want to set up another stick for UEFI boot(you can turn off secure boot on the customer's machine temporarily) and GPT.  I've just been playing around with bootable USB and even W7 Pro x64 will not boot from the stick when everything is properly formatted.  It gets to the Starting Windows and hangs.

You may want to put some W8 utilities or a UEFI bootable Linux on the stick to service those on W8 and later,

I haven't played around with changing the setting to Legacy Boot because I want VHDs that will boot from the boot manager screen on startup.

-MilesAhead (April 24, 2015, 05:45 PM)

Thanks for the tip, that's not a bad idea either. But I might have to just make usb images and switch between them for W7 and W8, since the only flash drive aside from this one is 4 GB, and I believe that ain't enough.
As for your problem, did you by any chance use it on a 3.0 flash drive on a 3.0 port? I've heard some complains about Windows installation freezing in that case, because Windows doesn't have 3.0 drivers inserted, they need to be added manually for it to work. So maybe you'll find this helpful if that's the case!