Finding a locksmith downtown can be pretty tough, especially online as most mom and pop shops don't even have a website or email address either.
Here are 3 locksmiths and key cutters that I have used that service Yaletown, Downtown, Coal Harbour, the Westend, and Gastown as well.
AL Scott Lock and Safe Ltd
102A - 505 Burrard Street
604-685-3138
http://www.alscottlock.com/
A-Ok Locksith 24 Hour Mobile Service
604-451-3399
Devak Lock & Key
604 669 6947
Mon-Sat 10am-6pm
1030 Denman Street
Vancouver BC
http://www.denmanplacemall.com/directory.asp