Third time's a charm?

Tried this twice already. Both times I quit before the first month was up. Going to give it another go for the third time.

A little about me: I'm 34 years old, live in Montreal, and work at a desk job all day (terrible for health). I absolutely detest going to the gym, so I try to fit in activity that doesn't feel like exercise, such as cycling to commute, walking or using transit, etcetera. I downhill ski in the winter and am trying to get back into shape before ski season starts. I also love to travel, and I tend to lose weight when I travel since my activity level skyrockets by walking around sightseeing and climbing ancient ruins and stuff, but then I have a bad habit of gaining it all back again once I get home. My major food weakness is chocolate: I have no power of moderation when it comes to snacking on cookies, brownies, ice cream, you name it.

My interim goal is to lose 10 pounds by Christmas, and another 5-10 on my Christmas vacation while I'm away, so 15-20 pounds by New Year's. It should be attainable, too; the first 5'll come off easy 'cause I'm at a post-holidays weight high right now.

The hardest part for me -- and the reason I quit the last two times -- is that I find tracking all the food to be pretty time-consuming and cumbersome. I'm a social person and I eat out a lot, so estimating portions and ingredients from restaurant food is tricky -- especially since it's extremely rare for me to eat at chain restaurants, and local restaurants don't provide nutritional info for their food here. I also don't eat a ton of packaged food, so it's not so easy to just scan a bar code. I definitely lose weight when I track calories, because it stops me from eating that extra muffin or having that extra beer. But I wish there were an easier way to make it fit in my lifestyle without putting a damper on my social life.

Anyway, let's see how this goes...