Lukas Smith has posted about some updates for the MDB2 PEAR package he maintains, including many bug fixes and the addition of the SQLite driver.
I got annoyed be seeing the driver fail so many of the unit tests because there is no support for ALTER TABLE in SQLite version 2 that I sat down and wrote up an emulation for it. Maybe someone has use for it.
There is a lot of tricky code in there to properly read the current table layout like fields, indexes and constraints as well as the data which all should be merged with the changes if everything goes as planned. Needless to say its a somewhat risky operation, especially since SQLite does not support transactions for DDL operaitons.
He also talks about some updates he's made to the LiveUser and LiveUser_Admin packages to correct bugs found there. His next release will be the MDB2_Schema package, with some new DML additions.