Pure telemarketing, in violation of the Texas and National Do Not Call lists. The company is Go Green; they seem to be calling here now on the average of every 15 minutes. They are serious pains in the [***] and just won't take NO for an answer or stop calling.
Lots of information about these sleazeballs: http://gogreen-marketing-solutions.pissedconsumer.com/go-green-marketing-solutions-houston-texas-20100908197590.html
They were calling Dallas area on June 21 2011 trying to set appointments for "free energy audits" and acknowledged they were flagrantly (and illegally) calling numbers on the Federal and Texas "do-not-call" lists.
They told me they were based in San Antonio, which seems to be a lie, too.
Why doesn't our state government come down on sleazeball scofflaws like this???