CL65 Captain reports unstabilized approach and landing. The poor performance is attributed to fatigue caused by 4 days of flying with the last day experiencing many delays due to weather.

Narrative

4th leg of a 5-leg; 11-hour duty day. Weather was low IMC for all previous flights; delays and ground holds were piling up. The entire crew was beginning to feel fatigued. This approach and landing was in VMC; so we were probably a little complacent and relaxed. Flight was cleared for a visual approach. First Officer was pilot flying. Pilot flying commenced visual approach according to company profile. Pilot flying lined up on final approach at 3 miles out; around 1;000 FT AGL. Flaps were at 30 degrees. Aircraft was about 30 KTS faster than Vref. At 500 FT AGL; I made the appropriate callout; and emphasized that the aircraft was 20 KTS above Vref. At this moment I realized that the flaps were at 30 degrees; not 45 degrees. As I announced this fact and selected flaps 45 degrees; the GPWS alerted 'Too low; flaps.' The flaps were at 45 degrees and the aircraft at Vref at 200 FT AGL. Aircraft landed without incident on the 10;500 FT runway. 2 factors contributed to the Crew's lack of adherence to SOPs. 1) Fatigue. Poor weather; a long duty day; 4th consecutive day of flying; 20 hours of flight in as many days; and lengthy delays all contributed to a fatigued crew. 2) Complacency. The first visual approach in VMC during 2 days of poor weather lead to the crew being more relaxed and complacent. I; as the Captain; should recognize these issues and work to prevent them from compromising safety. It is difficult during long duty days and flight hours to be 100% alert and energetic. Duty; rest; and flight time limits are past due for review and overhaul to reflect realistic human capabilities.