you'll find that pipeline patrol, and other "patrol" type flying is mostly going to require higher than 300 hours. for example, the local pipe company where i live considers applicants having 1500+ hours. also, word on the street is that you also have to be ex-military to be considered at this particular operation. now, the flip side of that is that the pay is great for what you are flying. most of the people i see in these positions are career types, and considering the pay and benefits, why shouldn't they be.
now, i second dropzone.com for sky diving, and i also know that you can tow banners with pretty low time, but seriously, instructing is an awesome way to build time. there was a stretch when i was instructing for a living, that i billed over 100 hours a month for several months in a row. that adds up! the catch is not to be the lame a$$ instructor who bails out on 4 hours of instruction to go log .8 in some friends ragged out pa23. you want to be the instructor who is there when the other guy's stood up students show for their lesson! i know that the other instructors i worked with hated me. it didn't take long before i was personally giving more dual than all of the other cfi's at this particular school combined!
you too can have some success instructing. the key, as with anything, is to keep a good attitude, focus on why you are there, and remember that being a cfi is so much more than a time building obligation. if that is all that it is too you, then by all means, please don't do it.
as for the specialty low-time flying job website, i have never seen such, but maybe you could start one!
good luck and best regards.
casper1nine