As GleeM said the PS3 and the GPU client can only do one type of simulation each, while the good old CPU client is used for the majority of simulations.
The SMP client, which runs on multi-core CPUs is also a high speed client, which means that it has very short deadlines, that way the whole process (folding-->paper) is much faster. SMP is very flexible (in terms of simulations) and will eventually replace the regular CPU client.
Don't be fooled by the Tflop/Pflop performance graphs, the CPU client will never be replaced and is still crucial.
Rosetta@Home is a similar project, but instead of simulating what nature does, rosetta bases their folding method on what they learn from nature, ie they create new proteins and fold proteins "blind" to fight diseases, while FAH folds proteins according to nature and study misfolds and how to prevent them.
Another worthy project (in my opinion) is WorldCommunityGrid, by IBM (runs on boinc too).
This project runs currently 4 projects:
Human Proteome Project (based on rosetta, analyses proteins of the human proteome and tries to find the cause and solution to various diseases by this analysis)
FightAids@Home (tries to find molecules that block the hiv protease)
Discovering Dengue Drugs ? Together (tries to find possible cures for dengue fever and related diseases)
Africanclimate@Home (studies the african climate in more detail than climateprediction, it is the most detailed study on african climate ever made)
A cancer project will follow soon. You can opt out of one or more project in your account.