As an example, an AXICOM / TE Relay Products V23079-B1201-B301 / 3-1393788-3
5V coils (one to latch, one to unlatch), 28 mA on either coil, DPDT, contacts rated 2A@30V-DC, 4ms response time
(this is the THT version, but they make an equivalent SMD)
The voltage/current rating is well within the operating limit of any ATMega 5V cpu. There is also a 4V coil version, that should function at 3.3V
The nice part about this relay, is that once latched, it consumes no current until you decide to pulse the unlatch coil.