I've noticed allot is usually used as an adjective (as in, "your allotted amount"), and allocate is more often used as a verb (as in, "I will allocate some resources"). Any other notable differences?
According to Wiktionary:
Allot should only be used when a collection of items is divided up into equal-sized chunks ("lots"), and then distributed. Allocate is more general in that it describes distribution, but has no requirement that the total set of items be divided into lots.
Therefore, allocate is more likely to be used in cases like computer memory, where a program asks for a given amount of memory from the free store, and that amount of memory is returned. But allot is more likely to be used in cases such as a "allot each person 50 pounds of grain per month".
According to a couple of dictionary sources (since the question stumped me), there is a difference in these two words.
"Allocate" means to set aside for a specific purpose, to fix the place of, to locate. "Allot" means to divide or distribute by share, to appropriate for a specific purpose, to set apart or dedicate.
Very close, but to me the difference is in this sentence. "The Parks Council has allocated 10 hectares of XXX Park for community gardens. The garden was divided into 10 plots which were each allotted to a specific local charity."