in reply to
Parrallel installation of ActivePerl 5.8, Strawberry and ActivePerl 5.10
Officially (for reasons I won't get into now, but basically because I say so) Strawberry Perl cannot co-exist with any other Perl installations on the same machine, including cygwin.
So from an officially-supported corporate-friendly perspective, my recommendation is that you install Strawberry 5.10 on a virtual machine (VMware, etc).
If you are happy to void the warranty (to the extend that we have one) then the above recommendations seem fairly reasonable.