Sniffing is actualy like listening to all the network traffic going through a certain point of a network. If you take a look at the osi module, and at the basic functionality of routers, switchs and hubs, you would clearly see why sniffing from a "remote" machine(assuming "remote" means across a router or switch) is not possible. however, if one was o gain access to the switch of the "sniffed" machine, one could surly view all traffic destined to and from that machine.

usefull sniffers:

Windows:

netXray, SnifferPRO
Iris

Linux:

etherape
sniffit
ethereal