Figure 1 Typical sample of people flaunting delightful beverages, while others remain beveragless.
First take a survey of all of the individuals in a certain radius from your location. Scale the individual’s movement vectors with the quantity of their drinks and average to obtain a single vector. This vector will show the average movement of the alcohol near you.
Once at the new location a new survey can be taken yielding a second mean alcohol vector MAV. Furthermore by comparing the overall glass levels at both locations one may extrapolate the location where the glass levels would be full, and presumably this would also be the location where you would also be able to obtain a full glass.
In the extensive testing conducted by the author, this method has typically worked in as little as a single iteration and as many as 4. This is most useful for items with a known maximum and minimum such as beverages, but can also be used to locate cheese trays, chocolate fountains, or any one of a number of other items.
Special thanks to Rob Raguet-Schofield for providing the initial figure of randomized vectors, without which none of this would have been possible. Nothe that these figures are meant as a tool for explanation and may not be to scale. Please feel free to point out any questionable methods or overwhelming dorkyness in the comments section.