PlayStation Network Plus, first got announced at E3, however there wasn't much information available about it's benefits. Now though Sony has revealed information about PSN PLUS, so you know what you get for your money.
It you $17.99 for a three month subscription though you can also get a $50 subscription for a year which basically saves you $22 over the 3 month package if you use it for a year.
After launch, PSN PLUS will allow subscribers to get Wipeout HD for free as well as other games from Sony's PSP Minis range and some PS1 classics. Other features include free monthly games that are downloadable as long as your subscription lasts, 20-50% discounts at the PlayStation Store, early access to betas and demos as well as a feature that allows users to auto-update games as soon as new patches and updates get released.
Lastly subscribers can even download games on a trial basis that allows them to play for an hour to see if the game is worth buying. If you buy the game after the trial period expires you can continue it from where you left it off in the trial.
Overall PSN Plus should be quite a good feature for PS3 users as it offers a variety of services for a small price.