I think your choice of software depends a lot on what you want to do. A one
size fits all approach is bound to require major compromises. My most
extensive experience is with Authorware. My ed version cost a little over
$100. I chose it for its facility in combining pictures and text. What I
have used it for was to create geology field trips in a box. My view is that
virtual labs are a poor substitute for real labs, but in my case it is not
possible to take my students to prime sites all over the world so I've done
my best to bring the sites to the students. Authorware makes it easy to
create interactive activites. We've used it to do some intro chem stuff and
also bio for activities that were visual or image intensive. For example,
rather than using limited lab time to haul out equipment and explain it to
students, we put pictures in a computer and students can go through on their
own time at their own pace and learn names, uses etc. In Bio rather than
prepare samples, specimens etc. for every student every semester we can do this
once and photograph what we want the students to see, saving a lot of prep time
and money. This is hardly a substitue for real labs, but students might
actually do one real lab and then go through several related computer labs
getting a broader exposure than would be possible using only real labs in the
same period of time.
Putting together anything that is really good takes orders of magnitude more
time than you would ever imagine. You can only justify the effort if no
commercial product is available, you do not value your time, or the creation
process itself has value. Probably the best thing to do is to let the
students create the virtual labs. Then they have to think about what the
point is rather than mechanically whip through something where someone else
has done the thinking. In the case of physics, it seems to me that there is
a lot of stuff like interactive physics availble. However, my feeling in
general is that with limited lab equipment and budgets even the most primative
real lab is more meaningful than most virtual labs and the virtual labs
should be used only as a supplement or extension of the real lab. I'm
inclined to view virtual labs as more of a substitute for lecture demonstration
s than as a substitute for real labs.