Hi Bob,
one option I've used applies to older small tube scopes eg. 4 x 20 Nikko Sterlings or old 3/4" tubed Weavers. With these the objective lens is fitted into a separate section and threaded onto the main tube. A bit of trial and error with fitting an "o" ring or suitable washer on the threaded portion will give a closer focus and is easily reversible.
The only drawback is these smaller scopes are not the best for indoor use, but some are useable.

Cheers
torrens