This site currently operates as the tileserver for the OSM cycle map at gravitystorm.co.uk/osm. You can find contact details on that site.
The tiles are available under the Creative Commons cc-by-sa license unless otherwise stated. You are free to save them and reuse them under the terms of the license.
Additionally, you are free to reuse/embed the tiles directly on your own website, as many people already do for their sites. This service is constrained by how much bandwidth I have available - if you use too much (roughly several thousand visitors per day will count as "too much") then we'll agree a better way to do things. If you want *all* the tiles for some reason, please don't scape them off the website, there are better ways to do things, so get in touch. And using them directly means your website users will get updated maps every week without you having to do anything!