As you are aware you need to pony up some cash to play most online games on the PlayStation Network, apart from one of two free-to-play titles all them require a PlayStation Plus subscription, including Grand Theft Auto Online.
Hidden away on a blog post on the North American PlayStation Blog is the news that from now until August 6th you will not need to PlayStation Plus to take to the streets on Los Santos and murder a hooker or two. Alternatively, you could try out the new nightclub expansion, After Hours, which includes tippity-top hip-hop happening DJ’s who will play in your club.
The European PlayStation Blog has not reported on the same news so the offer may not work outside North America, or maybe our PS Blog is just being tardy as usual.
UPDATE: They were being tardy. Now confirmed for Europe as well.
Source: PS Blog