PCB Manufacturers

UK

Screenbond 1 and 2 layer, low tooling cost and cheap for standard turnrounds, can do 24hr turnround.
Stickleback They have a prototype service via their Ebay shop
PCBTrainOnline PCBs and assembly service
PWTFull range of PCB services, including flex and aluminium
Tecbridge
Spirit circuits
Anglia Circuits
ABL Circuits
Cleveland Circuits
PCB PanelFlat-rate panel service
Quick-teckPCBs up to 500x630mm

SMT StencilPolyester stencils
DarkmassPolyester stencils
TecanStainless stencils, screening cans and photochemical etching
Spark LaserStainless stencils
PCB TrainStainless stencils
Solder ConnectionStainless stencils
QuickStencil$99 Stencil Kit

Advanced Circuits Full range of prototyping/production services based in Colorado; popular amongst university students.

Lueberg Large PCBs up to 1200x3000mm
Multi Circuit Boards Ltd. PCB prototypes and series with 1-48 layers; Online Calculator
Olimex
Eurocircuits

http://www.pcbzone.net/ PCBZone - Oz/NZ based panel sharing proto service.

http://www.circuitlabs.co.nz/ Circuit Labs. The commercial arm of PCBzone above. For bigger qty. Made in NZ.

http://www.acetronics.com.au/ (simple PCB's, assembly, silk screen NC mill etc)

PCBCart Long established Chinese supplier, with wide range of options at good prices, even after shipping costs.

Eurocircuits Wide range of prototype and production services including aluminium, also stainless solderpaste stencils.

PCB-Pool Pooling service, with free stainless paste stencils.

ITead Studio Very cheap two layer prototype service.

Seeed Studio Cheap two layer prototype service with thickness and surface finish options.

DorkbotPDX Two and four layer pooling service.

PCBwing Similar to PCBcart online proto service.