since at one point i asked the same question (very early in medical school), i will attempt a serious answer.
ob/gyn training consists of 4 years... the first 2 (in general) are spent managing pregnancies/deliveries, clinic patients, floor patients, etc... in essence they are non-op years. sure you will get to scrub in here and there on some hysterectomies, and probably a fair number of colposcopies, but most op exposure is limited.
in the last 2 years, you will get formal surgical training. the total abdominal hysterectomy and bilateral salpingoopherectomy will become your best friend. you will also do a lot of caesarean sections. probably do some purely ovarian cases as well. i don't know what the rrc numbers for ob/gyn are like, but whatever they are you'll have to get them in year 3 and 4.
so, in essence, you will only get 2 good years of surgical training doing a (compared to general surgery) narrow scope of surgery. this has some important implications. one of them is that the people who are training you have the same type of surgical training as you will be getting: ie. not much. you cannot learn to be a "surgeon" in the way that we think of the term in a mere 2 years. you will find that there are *many* differences between ob/gyn attendings in the or and other surgeons in the or. i won't get into that here... you'll see for yourself during your rotations.
if you find out in the middle of your ob/gyn residency that you really love the surgery aspect, but not so much the labor and delivery/vag itch aspect of the job, then you will probably lean toward the only hard core surgery fellowship out there for ob/gyns... gyn/onc. unfortunately gyn/onc is a very small field and a fellowship in this field is difficult to get. however i have found that gyn/onc surgeons tend to be way more similar to other surgeons in their skill levels, and technique.
in support of ob/gyn i will say that there is the potential for excellent continuity of care. you have the opportunity to get to know your patients extremely well (and their growing families). and for someone who truly is only interested in the female repro. system, he/she might be satisfied with the minimal surgical aspect of ob/gyn. and there are other fellowships one may pursue after an ob/gyn residency which some people think are pretty cool, e.g. maternal fetal medicine aka "mfm".
at any rate, there are some similarities between the fields, but now that i am firmly entrenched in my own general surgery residency, i believe that there are way more differences and that if you are considering both fields then you would probably be happier in general surgery. otoh if the thought of delivering babies, and doing vagitch clinic really fire you up, then ob/gyn would be a solid choice.
best of luck.