What you're actually seeing here is a different display of the title in Google's search results, rather than the title itself actually changing.
There are a number of ways this can happen - Google can use the title from a directory like the Open Directory or Yahoo directory, and Google also rewrites title elements to what it believes are the titles most relevant to users.
Remember that the content you see in SERPs is context-specific - it depends on what you search for.
In your examples, if you search for the actual words within the title, you're likely to see that displayed in results instead, since Google wants to 'give you want you want'.
Mod note: Let's try to avoid specific examples if possible!