Intermitten RPM surging

[oso]

As it always is the case with intermitten problems, I am having a hard time trying to figure out what may cause my car the sound and act as if someone has suddenly stomped on the gas pedal while I am simply sitting at idle or just shifting into the gear? That sudden surge comes and goes without any rhyme or reason ( at least to me...). Has anyone experienced a similar predicament? Any help solving the problem appreciated.