Faced with an increasingly effective military response, the FARC seems to have regrouped closer to the Venezuelan frontier, and has even been found operating base camps and such in western Venezuela. The FARC has been able to bribe corrupt Venezuelan military and political officials to secure a fair measure of immunity for its people in Venezuela. It's not clear the extent to which the Venezuelan government is actively favoring the FARC. While Venezuelan president Chavez is probably not adverse to meddling in the affairs of his neighbors, particularly if it irks the U.S., the FARC could pose a threat to Venezuelan security. Reportedly there have been some clashes between FARC personnel and Venezuelan security forces.
It seems likely that the Venezuelan government is underwriting some rebel movements in other Latin American countries. Colombia seems to believe this is true, and at least one revolutionary group in Ecuador has proclaimed itself a "Bolivarian" movement, while establishing covert ties with representatives of the Venezuelan embassy. It's not clear how far this effort to reach out to revolutionary groups goes, or how successful it may be, given that the insurgents in countries like Colombia, Ecuador, and Peru, are divided ideologically into often mutually hostile groups.