Learned-Learnt

Besides this verb, what other verbs when being in simple past change that way from a American to British.

Another example:
spelled-spelt

Here are some more.

blessed / blest
burned / burnt
dreamed / dreamt
dwelled / dwelt
girded / girt
kneeled / knelt
leaned / leant
leaped / leapt
smelled / smelt
spelled / spelt
spilled / spilt
spoiled / spoilt

http://www.sgbox.com/englishgrammar.html
http://www.eslfocus.com/grammarfolder/irregverbgroups.html

And then there's "cleave".
Past Tense: cleaved, cleft
Past Participle: clove, cleaved, cleft, cloven

Americans tend to use "burnt" as an adjective.

"The house is burnt."

"He's burnt out."

However, this is more often used in speech. When writing, "burned" is usually used.

>>> Americans tend to use "burnt" as an adjective...However, this is more often used in speech. When writing, "burned" is usually used. <<<

True. In my neck of the woods (L.A.), even though we spell the following words "dreamed," "leaped," and "blessed," we tend to pronounce them the British (RP) way. Although, I have heard many fellow Americans also pronounce them as "dreemd" and "leept."