milosevic - 12:44 pm on Aug 26, 2010 (gmt 0)
I just saw this and thought it was an interesting topic, I also wouldn't agree with some of the advice given so far!
Google is generally considered to (nowadays) use size and colour contrast of text to determine intended purpose/significance, rather than if it is a heading tag or not. This is likely to be because misuse of heading tags is so widespread. I still fully believe in a correct semantic heading structure, but not really for SEO reasons.
So making a big h6 above a small h1 is pointless, because Google will consider the h6 to be the main heading and the smaller h1 to be less important.
This means option 1 and 2 are basically exactly the same option. I can't see any real world difference in how they would be handled by Google.
I'd say option three is definitely the best for SEO and good design practice - Option 4 is overkill on the paranoia front.
That is presuming your intention here is to have a user-friendly piece of text (in the image) and search engine friendly text in the h1 (a few people have given advice as if both elements are being used for SEO).
Search engines can basically only read the alt attribute of the image so you could use whatever you liked as text without fear. 'hiding' the image is unnecessary, at least until Google add OCR technology to their spiders!
I think Option 3 is a great solution for 90% of situations.