You can get them in 3 months, but it will take a lot of work.
To do it, drop your calorie intake by 400-600 a day. And most importantly, run run run. Light jogging for 30 minutes will not do the trick in this amount of time. Try running 5-10 miles a day 5-6 days a week and then jog for 3 mile on your "off day". I know the 5-10 is really hard, but you can do it. I would advise not trying it immediately if you are not in great cardio health but search the internet and forums, and try to get on a good running program. You will need to push yourself very hard to achieve goals like this. In order to do this, I highly suggest that you stretch your legs and abs twice a day and buy a very good pair of running shoes. If you spend a little time doing research and browinsg the web you can find the right pair and relatively cheap (most good shoes are between $80-200). This is incredibly important and not to be overlooked or else you could injure yourself very badly.
As far as lifting goes, you need to vary your exercises (don't do the same exercises for more than 2 weeks in a row) and you need to do several to target all portions of the abs. Again, with a lot of research, try to find every exercise imaginable and try them out. You will obviously have to do ones you don't like (thats exercising for ya). Also, much like lifting with any other body part, if you want to see them, they need to get big, and to get big you need to constantly increase the weight being applied. I suggest weighted crunches and russian twists, v-ups, bicycles, the works. When working the abs, doing as many regular crunches or sit-ups will not get the job done, but it will build endurance.
To get serious about it work out your abs for about 20-30 minutes (that excludes rest) 3 times a week. When starting out, I would should for a little smaller of a time.
With this, a good diet, the proper exercises (and don't forget to continue lifting the rest of the body), you could possibly achieve your goal. Even if you do not, you will be happy with the results and it won't be long before you get the abs people jut talk about.
Good luck