Things that affect your ranking

I'm talking way off page factors here

[Powdork]

There has been a lot of talk about what we can do to help our rankings on Google. Lets now come up with things we can't do that affect our rankings. Usually these will be determined in some way by the end user. Feel free to throw in any ideas that come to mind (except Dominic) or correct anything wrong. I'll get started.
1. Where they are searching from (country)
2. What datacenter they hit (to do with freshbot, not dominic)
3. What their # of results is set at.
4. Is safe search on or off.
5. Are they using the toolbar?
6. Wireless?
7. Their previous query. (you never know)

5 & 6 may or may not have any affect, but probably send you to an often different datacenter.

Any other ideas

[mil2k]

8. Special queries and advanced queries of users.

[MHes]

8) Search phrase used (some people use very stupid search terms)
9) Connection speed (people will search more if its quick)

[Powdork]

#7 should have read query(ies)

[Hagstrom]

• 8. Language tools:
  
• 8a. Search pages written in <language>
  
• 8b. Search pages located in: <country>
  
• 8c. Use the Google Interface in Your Language
  

[Powdork]

8) Search phrase used (some people use very stupid search terms)
9) Connection speed (people will search more if its quick)

What I'm referring to is something that would cause the serps to be different, given the same search. For instance, search for blue widgets and then change your preferences to a results per page of fifty. Notice the difference. A site that has a page at #2 and #49 will now occupy #2 and #3 (not from the blue widgets example) with the indented results. This will displace all the sites between #2 and #49. It can produce dramatic differences.
I'm in a quagmire here. Is it ok to tell people to search for blue widgets when you mean it?;)