Paul Schlyter wrote:

The best candidate is Alfa Centauri, but perhaps you don't live far enough
south to be able to see it.

I wish! Perfect candidate for my amateur scope. [It's the target system
in my new sci-fi novel 'First Ark to Alpha Centauri' :-) ]

Other candidates could be Xi Ursae Majors and Gamma Virginis. The latter
is very near perihelion right now, and the separation is so small that
you'll see it as a single star. But do observe it every year during the
next decade, and see that "single" star split in two!

Yeah, Gamma Virginis is another pair I'm keen on following. I checked
the ephemeris predictions from the US Naval Observatory's sixth orbit
catalog:

http://ad.usno.navy.mil/wds/orb6/orb6ephem.html

The PA (degrees) and separations (arc-secs) are going to be as
follows:-

2005: 168.1, 0.381
2006: 85.8, 0.439
2007: 50.5, 0.726
2008: 35.2, 0.997
2009: 26.2, 1.238

Luckily for me, the two stars are of near-equal brightnesses so I think
in the next couple of years I'll start to see Gamma Vir as a 'double'
for the first time...

AA
http://www.publishedauthors.net/aa_spaceagent/