One way to check for a blown head gasket, is to simply smell the coolant reservoir. Pop the cap, and see if it smells like raw gas. Every headgasket, I've diagnosed has had this smell, even if the oil is not contaminated. Another way is to hook up a coolant pressure tester, and run the vehicle for 15-20 mins or so. If the head gasket is blown, the pressure will exceed 15 psi. sometimes as high as 25 psi. If there is oil in the coolant overflow tank, the head is cracked, about 90% of the time.
I'm working on a 03 Saab 95 2.3l t. This vehicle smokes on initial start up, then the smoke disapates, and the vehicle is fine. Another mechanic diagnosed it as bad valve seals. I disconnected the pcv system, and the vehicle no longer smokes. If the valve seals have gone bad, the vehicle will smoke on acceleration. Also if the turbo seals are leaking it will smoke more heavily on acceleration.

I am going to have to go with Toyota Ed on this one. White smoke almost always equates to coolant in the combustion chamber, while leaking oil seals in a turbo will normally create a sooty dark exhaust smoke. Additionally, I have never seen a failed turbo lead to a head gasket failure. All this said, it is still remotely possible that the turbo is failing, although one would expect to hear some slight increased turbo bearing noise and possibly some loss of boost if the turbo were failing.
Check the coolant reservoir to see if any globs of oil are floating in there and check the oil to see if the oil has become a milky brown color. If either of these signs is present, it indicates cross-contamination between the cooling and lubrication systems, thus pointing to the head gasket. The surest way to diagnose a failed head gasket, short of removal and visual inspection, is to have a leak down compression test performed.

Generally, this issue is one of two things: a head gasket (or cracked, warped, head) issue, or a turbo issue. On the 95 turbo models it is very difficult to distinguish which issue however. Lots of white smoke leans towards failed turbo and puffs on start up and acceleration lean towards head problems. If you can not tell, start with the cheapest job and go on until it is fixed - it does not hurt changing both as a failed turbo will eventually ruin the head as well, so kill both birds with this one stone.

I assume that when you say white smoke, I also assume that the smoke is from the tailpipe...
Check the coolant level ASAP.
White smoke is normally coolant getting pumped thru the engine, and out the tailpipe. This is BAD NEWS if the coolant level is very low. Check the coolant level & get back to me.

The breather fall off rocker cover and put it back on and it filled the hole road up with smoke

I Own a 99' 9-5 V6 Turbo SE.  This is what I know for sure.  Large volume of white, acrid smelling smoke (some loss of power) at start up and at idle sometimes.  With no other pattern or regularity is coolant leaking in through your head gasket.  Oil will be fine, coolant will be fine (for awhile).  Then you'll notice that your filling it more often, and more often over a long period of time. The pace will pick up(filling) until your sensor goes for $340. at that point the mechanic will get that look, do a compression test and tell you the happy news.  Cost to replace??  Don't ask. 

I have a 9-7x Saab and about a week ago white smoke started coming out of the pipe and it's pretty heavy white smoke. There is no unusual smell and the smoke only comes out when the car is started. I took it to the Saab maintenance and they can't figure out what wrong with it but states that they've had similar problems (don't understand why they wouldn't know??). Their asking for a $2500 authorization to tear my car apart to find out the problem and I don't feel that it's warranted for a break down of my car. Please help advise.

White smoke is water/coolent= blown headgasket or cracked head.
blueish smoke = overfueling
and black foul smelling smoke is oil burning= oilring

and very black sooty smoke and loss of power = turbo failure