A general discussion of birthday type problems is given and there is an associated applet. In the applet, the number of days in the year can be set from 1 to 400 (default 365). The number of people in the room can be set from 1 to 100 (default 20). The probability distribution for the probability of finding at least one match for the given number of people is given and a simulation can be run. Alternatively, the number of distinct values in the sample can be considered as the random variable of interest.