PlayStation®Plus - Claim your 30 day free trial This official Sony PlayStation link allows you to claim 30 day trial codes of PlayStation Plus use, which works with PlayStation 3 and PlayStation Vita. And, yes, it definitely works, the codes are sent within 24 hours. In my case it was just a couple of hours.
It only lists one country, United Kingdom, so I guess it also limits to UK members only. If you can get a proxy to bypass this you'll get a code.
If you want to redeem the code you need to enter your Credit card. I will not do that, done that with XBL & had problems when they charged for XBL while i didn't wanted that. I will never enter my credit card again on any online service !
Well, I just signed up for the free one month Xbox LIVE Gold that I had and afterwards I turned off auto-renew so it won't charge me anything once it passes the one month.