I was troubleshooting a client problem today and we needed to know how many total rows had been inserted into a table. It turns out you can use the show table status command to get this result.

show table status where name = 'tableNameHere';

This will show a bunch of information about the table and one of the columns is 'Auto_increment'. This is the field that contains the next id that will be used when you attempt to insert a row into the table.