-Ok Ok hold your horses.... you CAN flower from seed, but this is really only adviseable in situations where the seeds you are using require 12-14 weeks (I've heard of up to 16 weeks) to flower. This would be cool if you were growing some kind of haze or other long-flowering sativa variant. and keep in mind that you would probably not be cutting down on actual grow time any, the veg time is just replaced by extra weeks of flowering. the reason this happens is that long-flowering sativas come from equatorial zones where the natural light cycle is close to 12/12 all year long. If you tried this with an afghani or a skunk you would probably not get very much. Basically it only works well with tropical varieties.
-If you are interested in getting bud in 2 months from seed, try auto-flowering hybrids. I haven't grown from personal experience yet, but i've got 10 diesel ryder and 10 Automatic-AK47 x Automatic Hindu-Kush that just got to the P.O. Today and I've just gotta pick them up in the morning, Ill let you know if they are any good. I plan on crossing them, imagine that! Conventional wisdom dictates that the low-strength ruderalis used to pass on the autoflowering trait would create a relatively low strength plant, but people who have grown the hybrids swear they are just as good. apparently some really good people have hybridised the lowly ruderalis with potent sativa and indica plants, and even hybridized with other hybrids. If you plan on breeding tho, you gotta know a thing or two.