Having had the misfortune to deal with this outfit on Friday, i would advise any self-respecting teacher to follow the advice on this and other boards and avoid the place. After speaking with the recruiter (calls himself Ben) about summer work, i went for an interview. Ben operates from Beijing (010 number) so i met the COD and one of the CCS. The building is entered up a broken escalator which is covered in paint dust. The office looked reasonable, though there weren't any receptionists and the decor was about as inspiring as your average prison. After serving me with the obligatory glass of water, the CC told me that demo classes were very important and that i needed to do a good demo to get students. The COD then arrived and started asking me the usual insightful questions, such as: Can you speak Chinese? Unfortunately, Ben clearly hadn't told her about my background (more than 5 years in China) as she then asked me whether i'd ever taught before. We then moved onto the question of my availability - 1 or 2 months, which i'd told Ben. At this point the interview stopped as they were looking for somebody for 6 months minimum (Ben obviously hadn't told them i was only looking for summer work).

If the people representing the school can't clarify the length of time they want a teacher for before an interview then i'd have very little confidence they'd be able to do anything else properly (or legally) - like get you a visa or help you find accommodation. From what the CC said, you're obviously also going to be pimping yourself to get the punters through the door as well. There are far better schools in Guangzhou, so don't waste your time with Hampson.
Here's their address:
Yuexiu North Road, Dong Men Hua Ting building (2nd floor). The nearest metro is Nong Jiang Suo.