I've been thinking a lot about some of these questions lately  (and not just because I helped  draft the questions for the panel :)) specifically about when and how to introduce agile methods. One problem, which Roy points out, of fixed price/time projects (which unfortunately in Israel are pretty much the norm.). Another problem is with organizations such as the one I work for which have CMMI level 3 

(or more) certification (not to mention ISO 9002) which makes it really hard to introduce agility.

I stumbled upon this presentation  which analyzes the CMMI compliance of agile methodologies (I've started to try map SCRUM to CMMI 3 to get SEPG (Software Engineering & Practices Group) off of my back)

Another interesting approach I found is AgileTek's Agile+ methodologywhich is a mix and match approach that claims to be the best of both worlds (I am not sure I am 100% convinced but it is worth a look)

Lastly you can look at this interesting presentation by Barry Boehm and Richard Turner which talks about When to use which approach.