Vary your route and shift into low.
I have always ridden in very hilly, and sometimes mountainous, country. Alas, I've never been a great climber; but I have always enjoyed climbing in some weird way. I do get tired of it sometimes...especially while commuting. My commuter is not really set up for out of the saddle climbing, so I just shift lower, scoot back on the saddle, and settle into a comfortable pace.
My commute is only about 4 miles each way, but in the last half a mile or so I gain around 250 feet in elevation. I usually avoid the most direct approach, which goes straight up the steepest part. Most of the time I vary my route up the hill. Sometimes I ride up one block, cross over to the next block, then up again... zigzagging my way up. Other times I ride around the hill to a street that has a longer but less steep ascent.
For less steep, but long, climbs I may also vary the route from time to time. If you follow the same route every day, you know exactly what's coming and it's easy to dread. If you vary your route a bit you break up the monotony and the climb is over before you know it.
Triple chainrings are great if you haul a lot of gear on your commute. Using a super low gear will drag things out a bit, but if you can keep your cadence up you'll be amazed at how long you can pedal up hill. Start off in your lowest gear, concentrating on keeping that cadence up. After awhile you'll notice that you can keep the same cadence with the next gear, and maybe the next one after that.
Sean