We are still actively working on the spam issue.
Where Macs are hipster Facebook machines and ThinkPads are virgin 4chan machines, Toughbooks are for the clumsy, autistic, and "off-roaders." So, Toughbooks are Panasonic's line of tank-like laptops. They were first manufactured in 1996 with the CF-25, and as of today Panasonic still makes them. Current models are generally used in US military active duty, clumsy cops, and buisnesses who do "heavy work" (like painters/carpenters.)
A Brief History
1996: CF-25, first semi-rugged offering from the people in Osaka, Japan. Desgined to withstand 76cm drops, humidity and dust.
1999: CF-27, first fully-rugged Toughbook, first to offer a touchscreen and WWAN (Wide Wireless Area Network), IP53 water/dust rating.
2002: CF-28, first Toughbook to offer IP54 waterproof rating, and a sunlight readable transflective screen.
2003: CF-18, first Toughbook convertible tablet.
2006: CF-30, first Toughbook to have a 1000 nit screen, even more sunlight readable than anything else before.
Ensure you don't buy a Toughbook with a password-locked BIOS! You CANNOT reset them in any way as you can with Thinkpads! Same story with ones that haven't got a internal WLAN card in it, they are Federal models 90% of the time which have the WLAN slot BIOS restricted and you can't run a WLAN card in one, they will not work.
Try not to buy from a business seller, they tend to ask a lot more than private sellers. Businesses usually get them in bulk for cheap, and think they can pull a jew on you by bumping the price up 300$ or 400$ more.
Hard drive caddies for older models like the CF-18 and 29 are muchcheaper than newer ones for the CF-19 and 30/31. Yet, caddies from all generations of CF-19's are interchangeable, as they are all SATA. I am running a CF-19 Mk1 caddy in a CF-19 Mk5, the newer (Mk4 and up) caddy has a plastic casing and it sucks to take apart. The older ones are fully made from stainless steel and are held in place by two screws.
The CF-30 and 31 caddies are also interchangable as far I know, gotta do more research on that subject.
Older models, like the CF-18 and 29 tend to have broken/non working touchscreens, because of delamination, the Mk1 CF-19 had this too sadly.
Port covers from China are shit, get original Panasonic ones if you want waterproofness, the Chinese ones don't keep out the water and you will ruin your Toughbook when you get caught in a rainstorm that way.
Same story with batteries, Chinese/clone batteries and chargers for Toughbooks are shit and should be avoided. Need a cheap charger? Use a IBM 72 watt adapter from a older ThinkPad, like a T40. They also have newer ones with a built in car/12v cigarette lighter socket cable.
As for buying: eBay, Craigslist, and if you like rulefaggots: Notebookreview's Panasonic forum, careful though: mention BIOS and password in one sentence and the mods/99% of the users there will sperg the fuck out and will probably ban you.
Slightly better is Toughbooktalk, they allow BIOS password discussion but the owner is a huge faggot, and the atmosphere of that forum is circlejerky. Also, the owner doxed a user once (for selling overpriced shit, apex kek), tread with caution.
A good site for info about all sorts of rugged computers is www.ruggedpcreview.com, it's been here for a while and is still being updated.
To decode a modern Toughbook serial number, use this: http://www.panasonic.com/business/toughbook/order-toughbook-computers.asp
For older models, try the Toughwiki, a very useful source: http://toughwiki.com
So, you came to the conclusion you want a Toughbook? That's cool, what model do you want?
Just want one to mess around with? CF-29 Mk3-4 or a CF-18 Mk4-5, these all have PAE and can run Linux pretty good.
If portability is a issue: CF-19 Mk2, it has a Jewtel U7500 CPU with 64 bits capability, and a pretty good battery life.
Speed is a must: CF-30 Mk3, CF-19 Mk4 and up, or any CF-31.
Extreme portability and speed is no issue? CF-U1 Mk1 or 2, a rugged UMPC.