Google allows most businesses to verify their business listings with Google Places over the phone through a phone verification process.

When I verified my business, when Google Places was actually Google Local Business Center, they did not have the phone verification method. I used the old fashion postcard method in the mail that took a couple weeks.

But now, phone verification is fast, less expensive and easier for many.

However, there seems to be a bug preventing it from working for some.

Jay from the Google Places team posted a known issue report in the Google Places Help forum saying:

There is no ETA for a fix but someone did try it out over the weekend and it still was not working.

Forum discussion at Google Places Help.