I've actually known about free Regus Gold membership for a while, and it's very often offered as part of a deal between one of many loyalty programmes, including but not limited to: Priority Club, American Airlines, MileagePlus….even the Thames Valley Chamber of Commerce has its own free offering.
Regus is one of the world's largest temporary office space companies and even if you paid the full price for the annual membership, currently at ?500 per year (?35 per month plus VAT) it's still a very solid offering. This is very useful for mobile business people. (Or maybe you just want to drop in to have a quick cup of tea!)
Head for Points' article a few days ago inspired me to dig around for some current free codes, and promotional code
UKPFSB appears to be working [Sorry, this code is no longer working] (I sourced it from here) and gives Gold status for 12 months. Just enter the code in this signup link, and make sure you cancel before your 12 months are up otherwise you'll be invoiced with the annual renewal fee!
Enjoy another free gold status!