I am currently using Master-Slave Replication, separating reads from writes at the application level. The only kind of fail-over currently implemented is application level detection of master failure, making the slave the new master so the application can run uninterrupted. As one can guess, it is a lot of work to switch back, get in sync, tidy up and so on.
I have searched a lot, and read dozens of articles, but I did not come across a solution for HA MySQL if you have mostly MyISAM Tables, Mysql Cluster, Heartbeat/DRBD, Schooner, these are all fine for InnoDB-only setups, but not suitable for MyISAM.
I would appreciate some suggestions or real-world experience with HA Setups. It does not need to be open-source (read free), it just needs to work.