I always get skeptical when I see an article about "indespensible" travel gadgets. Too many times I've opened one of these up and seen references to designer laptop bags, the latest Blackberry model, or a portable speaker system. All things that have everything to do with taking home with you, rather than leaving the home life at home and going exploring.
Thankfully, this travel gadgets article from SmarterLiving is a different story. We could argue about whether you really need an alarm clock that figures out the local time for you--if you're making enough money to afford that clock, you're probably staying in a hotel that has a clock don't you think? But I'll admit I'd probably find the laziness quotient useful if someone gave me one of these for Christmas (hint hint to any relatives reading this...)
Same for the backpack with wheels. It seems that if you are fit enough to carry a backpack, the wheels are superfluous. But if you're dead tired and have a long airport terminal to get through, they could be handy. Best of both worlds if the pack still manages to be comfortable.
As for something that allows you to carry money under your clothes, that is indeed indisputably indespensible. Don't leave home without it.