Eliminate Casting Time:
Right after casting a spell, go to the
menu inventory screen. When you
return to the game, the spell will
instantly take effect. Use this trick if
you need to get off a spell immediately.

Dungeons & Dragons Spoof:
At the main menu choose to view the credits and then press X. You will be taken to
a hilarious animated skit of a few of the characters from Summoner playing Dungeons
and Dragons. 

Easy EXP and Bacite Tails:
Make sure your party is at level 13 or 14 and go to Ikeamos Swamp. Make sure
you have completed the ring of light quest. Fight the Bacites until you have had
enough and leave. If you kill all of them, leave and come back in. They will have
regenerated.