Sparky13 - not to be blunt, but you'd have to be blind to not see the phone numbers listed on each girl's page. For e.g., you go to
www.sex141.com, select "Yes I am at least 18 years old (Web version)", click on the photo of any of the girls that appears, next to the photo of the girls, is a table that lists the following:
Name:
Address:
Tel:
Hour:
Height:
Size:
Race:
Service:
Generally, just cal the phone number listed next to "Tel:"...
As for walk ups, recommend TST area. Do a search for "walk up" and select Full Body and then Hong Kong section, and that should lead you to the right place.