Relevant grammar question & comments here (second post).
Amatuka
ex#1078 can be also said, 赤ん坊は私の顔をみるなり、泣き出した。 hmm no entry for なり?
Miki
Is it always a "negative" sentence that comes after the "yainaya"? (ie cry, shut up, rain...)
Pied
My textbook uses kanji for this grammar - や否や. It also says that sometimes the "否や" is omitted - Aや、B.
blabby
Still it seems hard for me to difference the use ofや否や、かと思うと、なり、たとたんに. It's clear the meaning of the examples, but if I had to choose one of these in a blank, I'd probably fail.
poderesx
#pied, that is not necessary. Any action can come after や否や, like 'No sooner had he closed the door behind him than he burst into hearty laughter.' Picked this up from an old Japanese Sherlock Holmes novel I had.