Visa Waver form ?

Correct, and the newer landing cards are bigger and have a blue border with white boxes then the older all white landing cards, and I think they are in English, French and Spanish.  Maybe another language.

Excellent...then the OP has no worries!!

New landing cards are in English, French, and Spanish.  Information needed to be filled out on the card includes name, sex, date of birth, town & country of birth, nationality, occupation, full contact address in the UK, passport # and place of issue, planned length of stay in the UK, port of last departure, arrival flight # or train # or ship name, signature.  All information should be provided in English (important, obviously, in only a couple of places on the form, e.g., occupation, length of stay).

I don't believe there is any Spanish there, unless it's an extremely new version. It's in English. And in German and French!

Here's somebody's jokey filling-in of the new landing card. Ignore the writing and you can see what the average one looks like.

http://farm4.static.flickr.com/3536/3271005723_656cdf8a70.jpg

I stand corrected! Apparently they come in a lot of different combinations:

http://www.globalprintmanagement.co.uk/uk_immigration_cards.html

Funny that in all the years that I've been travelling to the UK from various places, I've only ever seen them in both forms in only English / French / German. Oh well!