We tried a Miyakidori which is a remote controlled, bullet vibe, with various vibrate patterns.

we never really got on with it very well... her favourite pattern was in the middle of patterns that she didnt like, and there was no way to vary the strength, or get directly to the preferred patterns (you have to skip through loads) and turning off the controller reset the pattern to the start again... so this device was used once and never again, shame it was really expensive.

But Id love to find one with a standard vibrate and a variable strength, so if anyone sees one please add it to this thread.