Check out gromitgirl's picture on her Flickr page
gromitgirl gets mentioned in first article about Steve Jobs Rainbow.
Former Google and Microsoft executive, Li Kaifu, pasted a photograph of a rainbow near Apple headquarters that a friend sent him.

from SFist.com
edit: from SFist article
(There is one error on the blog -- they've included the double-rainbow photo that SFist Jay posted, but the photo was shot yesterday, not on Wednesday.)

Hi there, I took this photo this morning while on campus. Little did I know how symbolic it was until I heard the sad news of Mr. Steve Jobs passing. -Aaron Miletich
Posted on the Local ABC-TV website
In extreme contrast to SFist Brock's collection of Steve Jobs backlash stories, we offer one from the opposite end of the spectrum.
In response to SFist Jay's lovely double-rainbow post from yesterday, commenter Appletwo brought our attention to Steve Jobs' Rainbow, a blog that chronicles various sightings of the rainbow that appeared shortly after the news of Steve Jobs' death broke on Wednesday.
via @justiceiscool
Wow so after hearing about Steve Jobs I see a Rainbow appear outside my office window. Is it in iRainbow? RIP again Steve Jobs
Via: elizaIO

[Pixar] posted on Monday a photo of a rainbow over their offices, with the caption, "A rainbow on a cloudy and sad day over our studio? Thanks, Steve. 10/5/11"