I finally got around to working on Stutter last night. I ended up spending about 8 hours straight converting it to work with PHP's shared memory functions.
For anyone who tries to use the shmop fu with PHP, be forewarned that if you shmop_write() a string called "foobar" and then shmop_write() to the same block another string called "bar" with a 0 offset, the resulting block will be "barbar" (which was not apparent from the documentation). In addition, when you shmop_read() from that shared memory block, the result will be a string padded to the size you have specified in the read operation. A liberal use of trim() and pad() are the apparent solution.
Of course, today I accidentally slept in until noon, almost making myself late for a meeting. Typical.