That might not be a problem in the USA, but it might be seen as poor etiquette in Asian countries. I know that the Japanese would be put off if you were to leave your chopstick stuck into a bowl of food because that is something that is only done at funerals (at least, with a bowl of rice). I have no idea what rules apply in other Asian countries, though.
Really, though, why not just grab a set of chopstick rests? You could probably get a set of two or four for $25, depending on material and quality. The cheap set of laquered chopsticks I bought (two pairs) came with a rest for each pair for under $10.