Hi, What is the best structure/way to create an array of bits (actually true/false flags) of an arbitrary length ranging from about 20 upto about 500. Speed of access more of an issue than compactness. eg: [0] 0 [1] 0 [2] 1 [3] 0 [4] 1 ... [n] 0 etc. Thanks for your input and advice. matthew.