What would you do without them? Seriously, if every single battery of every single type were suddenly zapped out of every single thing that it operated, what would any of us do?
The battery chemistry has 3 types: NiCad, NiMH, and Lithium-ion. NiCad, or NiCd, battery is used in older cordless drill tools. They are the least expensive, so almost all inexpensive cordless tools use this type of battery. There is one problem with this battery. It's toxic to the environment. So when it's time to dispose the dead NiCd battery it's a problem.
If you would rather prefer an entry-level dSLR, then you better get Nikon's D3100. It offers fast performance, superior image quality, and unparalleled control. It features live view, 1080p HD video, and a guide mode that is very user-friendly. It has a three-inch LCD screen, DX-format CMOS sensor, 1080p HD video, and is 14.2 megapixels. It uses a rechargeable lithium stock ion battery as well as SD, SDHC, and SDXC media cards. Nikon D3100 is one of the lightest and smallest dSLR's available. It is the ideal camera for frequent travelers.
The PrintStick is a mere 1" x 1.9" x 11" and weighs 1.9 pounds including the thermal paper and cartridge. It prints up to 3 pages per minute on 8.5" wide sheets. A cartridge will print 20 8.5 x 11 inches pages. Power options include AC 120-240, DC 12/24V, and rechargeable Lithium-ion battery.
The Lithium battery stocks-ion battery is light years ahead of the earlier batteries and considerably better than the Nickel-cadmium (Ni-Cd) or the nickel-metal hydride (Ni-MH) batteries which are still being used. These batteries are less expensive but the Li-ion batteries are far superior in three ways.
The battery will re-charge a little if placed on a hot surface, like a radiator. Never place a mobile phone battery on a hot surface! There is a significant chance of explosion with extreme heat. A modern Lithium mines Ontario battery becomes less efficient the warmer it gets.
To add spice to your inclination for mini size gadgets, there are mini phone receivers in cool color having an operational range up to 10 meters with adjustable volume and built-in 300 mAH rechargeable Lithium battery giving a talk time of over 5.5. Hours. These mini phones are compatible with Nokia, iPhone, Blackberry, Samsung etc. The Bluetooth version V2.0 is compatible with V1.1/1.2 and comes with one USB charging cable, one carrying strap and a manual to consult. Now, you do not have to leave your desk to instruct, chat or gossip.
Of course, there will be Apps. Smart phones right now are all about the apps. You need to do a bit of search. This is necessary since the right apps will help you and nasty ones will just be a liability and will eat up your space. There are also paid and free apps so if you really want to make the most out of your smart phone use, check out the options and invest on good ones.