spying tools:

procspy

apispy32 
ntspy

apimon

strace 
regmon
filemon

http://www.bindview.com/Support/RAZOR/Utilities/Windows/strace_readme.cfm
http://www.internals.com/articles/apispy/apispy.htm
http://www.internals.com/
http://cmp.phys.msu.su:8000/ntclub/pub/ntspy.html
http://www.wheaty.net/FAQ.htm
http://www.cmlab.csie.ntu.edu.tw/~jiajing/archives/000044.html
http://www.codeproject.com/system/Paladin.asp
http://www.codeproject.com/system/hooksys.asp

http://www.kakeeware.com/i_kam.php