Douglas Bush (MMD 00727) is right about the Sinsheim Museum being
easily accessible, but it is so not only by public transport.
Lovers of old cars, old planes, old trains and old music need only
drive along the autobahn from the Heidelberg area towards Heilbronn
or vice versa (route 6, if my map is up to date) to see the planes
displayed above the museum buildings.  Turn off at the next
junction (either way) and the museum is well signposted.

If you haven't got your own transport, try getting all your friends
to go at the weekend on the German railways special tickets (last year
costing 35 Marks -- less than 20 dollars) to take up to seven people
as far as they could go in a day.  We found groups of pensioners from
the Pfalz mountains going halfway across Germany for a walk by Lake
Constance and returning on the same day.  If it's too far to do that,
go on the Saturday and pay another 35 Marks for all of you to come back
on the Sunday!

When we enquired (disbelievingly) about the bargain in halting German,
the station computer at our small village printed out times of the
possible trains we could take and the changes we would have to make,
all in beautiful English translation.  The experience is thoroughly
recommended.

Tony Austin
UK