myisamchk can fix it
But be careful and use the right options to avoid losing data. In fact if you haven't you should make a backup or at least manually copy /var/lib/mysql.
Replace "YourDB" with the name of your database
Replace "yourcrashedtable" with the name of your crashed table.
The -o option is the safest and should avoid dataloss whereas -r is more aggressive and is a last option (I have lost data using -r and only discovered it later).
myisamchk -o /var/lib/mysql/YourDB/yourcrashedtable.MYI