Parents on visit - stayed with me for 6 months.

[shyboy]

My parents stayed with me for exact 6 months in 2010 on visit visa.

I totally supported them during their stay in USA.

Can i claim them as dependant ?

I did not get any notary while they were in the US. but i can get their entry/exit stamping on their passports. is this enough?

if yes then how do I get their ITIN #s. ? through W-7?

Is it wise to do that?