The top two comments say :

QuoteReally surprised at the number of pilots here who apparently don't know how to remove crab before touchdown. This is how nosewheels make lazy pilots - almost every one of those nosewheelie landings would have ended in a major ground loop in a taildragger.

The better way: crab until over the threshold, then upwind wing down, opposite rudder to keep the nose down the runway, touch down on the upwind wheel.

In a taildragger this is survival; in a nosewheeler it's much better for the tires.

and

QuoteIt is clear that at times the crosswind is out of limits for some aircraft, ZK-MDS for example (Amongst other 152's) had huge amounts of trouble negotiating a crosswind without adopting the "wing down method". The slower you go the less effective the Rudder becomes, so without the "wing down" method to supplement the rudder in those conditions, you will put sideways strain on the gear. (90% of the aircraft land sideways in this vid) Im sorry but this video frustrates me.

What does "remove crab" mean ?

it means looking london going tokyo

i.e nose of the aircraft pointing into the wind
and plane flying sideways on the landing approach

Nice tips in the quotes.
Remove crab means aligning the plane (nose) to the direction of travel just before touchdown. This picture explains it better

Usually for such crosswind landings rudder will be used more! either by applying primary controls(Whole rudder) or secondary controls (spring tabs or trim tabs) ! but before touch down you need to neutral primary control or set the secondary control to neutral!

crab looks in one direction and moves in the other! that's why its called "crab".

Apparently there are two techniques to handle cross wind landings, crab and sideslip. Wonder how they are different.

side-slip is very different that crabbing....

side slip is mainly used in gliders to loose  height and drop speed at the same  time by using the fuselage  as a brake to  create  drag.... the side slip induces a very violent vibrations in the entire plane. this is basically  used in  gliders where u  have only one chance to get the landing right.
not necessary be a crosswind condition this is even followed in a headwind to loose height  and drop speed at same time...
achieved by some thing called cross-controlling. in case or a right slide slip the elevator is slight  down, alirons left, and rudder to extreme right.

in  crabbing u just need align ur self in the direction of the wind and the runway... may look  similar but in this case u have no drag produced by the fuse  as u are into  wind.

real world pilots.... please  correct  me if wrong....

just a case of slide slip..... AIR  CRASH INVESTIGATION - GIMLI GLIDER

http://www.youtube.com/watch?v=ribT9NfkAsg&feature=fvst

http://www.flyrc.com/090932

http://www.nycaviation.com/2014/02/crosswind-landings/#.UwwRa_SSyCu