One of the coolest things going on the PlayStation 3′s PlayStation Store right now and for the last three weeks or so is the limited-time offer to download Gran Turismo HD Concept for free. Sure, the game is limited right now to about a dozen cars and only one track, but as a “play it now” glimpse into one of Sony’s most-cherished racing franchises and what the PS3 could hold for fans of the game, Gran Turismo HD Concept is an addicting teaser.

Now, it’s not a completely original-for-PS3 build. The game is based on Gran Turismo 4, with an extensive port-up makeover for PS3. And early rumors had it that you’d have to buy 100s of extra cars and dozens of extra tracks to race on via PlayStation Store “microtransactions.” Otherwise known as literally “nickle-and-diming you to death.”

The prospect had some people with dollar signs in their eyes scheming to find ways to make similar micro-transaction schemes involving everything from unofficial game mods to business card printing. Yikes!

So far, that doesn’t appear to be the case. The game is limited, seems to be little more than a tech demo, but is addictive fun for all of that. And it’s free. That’s nice. Now, back to our regularly scheduled time trial.