There are a number of interesting characteristics to at least some types of oil that make for interesting arguments against the abiogenic origins. Specifically, oil is a phenomenally complex set of hydrocarbons- not the least of which includes a fair chunk of aromatic compounds (benzene rings) that are highly unlikely to be formed in the absence of life. There's also little bits about pristane and phytane- complex markers that are characteristic of things like decomposed chlorophyll (chlorophyll -> phytol -> pristane, and chlorophyll -> phytol -> phytane) that simply shouldn't readily- if at all- be formed abiogenically.

It is almost certain that there are different routes to oil, so there is probably some that is produced abiogenically, and probably some from bacteria, and a lot from algae. Oil is highly variable, which is unsurprising as it is found under highly variable circumstances. Some of it has been found in rocks that are not the normal source rocks for oil; however, we know that oil "travels," and can come from sedimentary rocks, followed by it being squeezed and moving through different sediments until such point in time that it is "captured" in a reservoir rock or formation. Finding oil in limited quantities in extinct volcanoes need not be from abiogenic oil, although it seems possible under these circumstances.

The simple fact of the matter is that almost all recovery occurs from either deep ocean sediments (thus offshore drilling), or in reservoirs where geologists and geophysicists agree that it is highly likely that oil will be found. If this were not the case, we would find oil from just drilling willy-nilly, which although probably occasionally productive, is certainly not the manner in which most liquid hydrocarbons are recovered. It doesn't make economical sense as- quite simply- the oil is not known to be there. Lack of searching? Maybe, but that's not how the oil companies see it.

And the Laurie Garrett letter referenced to in the article on the World Economic Forum:

http://lists.topica.com/lists/psychohistory/read/message.html?mid=1711891071&sort=d&start=4389

Among other shining spots from 2003:

"- If the U.S. unilaterally goes to war, and it is anything short of a
quick surgical strike (lasting less than 30 days), the economists were
all predicting extreme economic gloom: falling dollar value, rising spot
market oil prices, the Fed pushing interest rates down towards zero with
resulting increase in national debt, severe trouble in all countries
whose currency is guaranteed agains the dollar (which is just about
everybody except the EU), a near cessation of all development and
humanitarian programs for poor countries. Very few economists or
ministers of finance predicted the world getting out of that economic
funk for minimally five-10 years, once the downward spiral ensues."

I saw this, and the first thing I could think of is how I want someone to design stickers- thin strips I can paste on every bill. The top one reads "THE WAR IN IRAQ" that fits over "United States of America," and "$3,000,000,000,000" that fits over the denomination at the bottom.

Lord Peter: I found it here.

http://tlo2.tlc.state.tx.us/statutes/docs/HS/content/htm/hs.006.00.000481.00.htm

I have no idea if it's been repealed or not.

@9: Not exactly what you want, but a copy of "Dick's Encyclopedia of Practical Receipts and Processes" may be of interest. You'll get a kick out of it.