What type of tech should we use in lessons, and when?

Preparatory questions and links:

Focusing questions:
What do you define as tech/technology?
What maths-specific technology do you need to teach? What technology would you like to teach?
When should technology not be used?
Can you, do you or should you use technology as much as possible?
What non-teaching technology do you use?
How comfortable are you with using technology? How about teaching with it?

What types of technology would you like to introduce tomorrow, this term, this year?
What are the main issues or concerns for not being able to use technology in your classroom?

(Provided by @ColinTGraham)

Threaded discussion from Thursday 19th August 2010 -
Threaded discussion from Monday 23rd August 2010 -

Links mentioned in the discussions, with contributor:
Thoughts on IT & Engagement (by @tborash)
Immediate feedback on quizzes etc. http://thatquiz.org or http://assistment.org (by @davidwees)
National Library of Virtual Manipulatives (by @tcash )
Glencoe/McGraw Hill virtual manipulative (by @tcash )
GeoGebraWiki (by @ColinTGraham)
Math help for Parents and Students Math A Tube (by @ghewgley)
Mathtrain.tv for student podcasts etc. (by @tborash)
Glogster with some examples (@grade1)
Wolfram|Alpha widgets (@georgewoodbury)
Helpful online math tools (by @cybraryman1)
Explanation of Champ or Chimp and an example (@grade1)
Mental mathematics below the list of 'tricks'! (by @cybraryman1)
Real Life Parabolas and Ellipses - video (by @shyj )
Carol Dweck talks about Mindset - Elluminate session (by @johnfaig)
SMARTboard podcast with maths examples (by @ghewgley)
Changing math word problems into video problems (by @davidwees)

Resources (costing money!) mentioned in the discussions, with contributor:
3D cameras (by @ghewgley)
Uno cards (by @Cassyt)
Numbers printed on perforated index cards (by @Cassyt)
Wolfram's Mathematica (by @mathheadinc )

Other links which may be useful