You can keep fish oil in the fridge to keep it from going rancid (probably a good idea for most oils that you use infrequently).
In regards to the risk of blood thinning, etc. Consider how much fish certain groups eat (thinking inuit, islanders, etc), I don't personally buy the blood thinning risk as being something to be real concerned with.
I think also that the 3 gram thing is 3 grams of omega3s, not 3 grams of fish oil. In your typical inexpensive (this is a relative term to the most expensive brands) fish oil supplements, you may only have 400 mg of omega3s. You could take seven grams of fish oil and be under the 3 grams of omega3s recommendation.
Also, when you consider the amount of omega3s found naturally in fish that many people eat every day, you will realize how little 3 grams of omega3s really are. Check this out (link to article after quote):
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">
Amounts of seafood necessary to provide 1 gram of DHA + EPA (based on USDA Nutrient Data Laboratory information): cod (Pacific): 23 ounces; haddock: 15 ounces; catfish: 15-20 ounces; flounder/sole: 7 ounces; shrimp: 11 ounces; lobster: 7.5-42.5 ounces;
sardines: 2-3 ounces; crab: 8.5 ounces; cod (Atlantic): 12.5 ounces; clams: 12.5 ounces; scallops: 17.5 ounces;
trout: 3-3.5 ounces;
salmon: 1.4-4.5 ounces;
herring: 1.5-2 ounces;
oysters: 2.5-8 ounces;
tuna (fresh): 2.5-12 ounces; tuna (canned, light): 12 ounces;
tuna (canned, white): 4 ounces;
halibut: 3-7.5 ounces;
mackerel: 2-8.5 ounces. Cod liver oil: 5 grams; standard fish body oil: 3 grams; omega-3 fatty acid concentrate: 2 grams.</div>
http://www.mayoclinic.com/health/fish-oil/NS_patient-fishoil
You can see that if you ate salmon, trout, sardines, or herring on a regular basis, you could easily surpass this "recommendation". Does anyone think it odd that a doctor will put your life at direct risk by prescribing drugs such as vioxx, but with something as simple and healthful as fish oil suggest you limit your intake to a fairly small amount?
Sorry, I just get tired of of the line toeing that so many doctors do, granted, they have to worry about lawsuits and such (which is more bs in my opinion, but anyway).
Check this out:
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">Bleeding : Intake of 3 grams per day or greater of omega-3 fatty acids may increase the risk of bleeding, although there is little evidence of significant bleeding risk at lower doses (245; 246; 247). Very large intakes of fish oil/omega-3 fatty acids ("Eskimo" amounts) may increase the risk of hemorrhagic (bleeding) stroke (92). High doses have also been associated with nosebleed and blood in the urine (147). Fish oils appear to decrease platelet aggregation and prolong bleeding time, increase fibrinolysis (breaking down of blood clots), and may reduce von Willebrand factor.</div>
The article mentions "Eskimo Amounts" several times but does not quantify how much this is. I'm assuming that it is significantly more than 3 grams per day of EPA+DHA.
I also think that the wikipedia entry on Omega3s is pretty good:
http://en.wikipedia.org/wiki/Omega-3_fatty_acid