CuRoi, thanks for the reply. I used to GM more like this when I GMed Rolemaster - although because RM PCs have a very long skill list compared to D&D PCs, sometimes skill rolls would also be made using relevant skills, and I would factor the effects of those rolls into the mix.I adjudicate what happens and not every idea is a winner or will effect the ultimate outcome. There's very little difference to the approach you took, except I place "fiction first" as it were and weigh in my mind whether the outcome will be successful before I decide how long or how effective the various implementations will be.
One thing that led me to 4e was the attraction of a more structured approach for handling these sorts of situations. So, to an extent, I've deliberately broken away from some of my past GMing practices.
One thing I like about the structured approach - and it resonates with things that I'd heard from others, and was one of the things that attracted me to it - is that there are clear multiple points at which the players can have input and try creative stuff, namely, every time there turn comes up in the challenge and they think about how to respond to the situation that I'm describing to them. So the structure helps guarantee a type of dynamism to the interaction at the table.
Before adopting a structured approach I'd had trouble getting this sort of dynamism - it was more a case of the players saying what their PCs do, and then me adjudicating it in a single step.
Do you have any tricks for getting this sort of dynamism with your approach? And to go back a step, do you care about this sort of dynamism, or are you happy to just adjudicate the players' plans in a single step?