Omnipresent, ubiquitous mean present or existent everywhere.
Though they carry this as a basic meaning, they are often used hyperbolically. Something omnipresent is present everywhere at the same time. Though basically applicable to the Supreme Being, the term is often, especially in a weakened sense, applied to something that is or is felt to be always present or existent (as in a class or a type wherever it may be found or in an area to which it belongs).
Something ubiquitous is found everywhere and, often, at the time or in the situation specified or implied.
Ubiquitous is applicable to a type or an individual, often with the specific implication that one cannot escape him or it wherever one goes.