to get the Spirit Lance you have to 'pray' at 3 Quactuar stones. there are grey blocks of stone with an engraving of a Cactuar on it. when it glows n u stand in front of it, press square n u will kneel down to pray <img src="/images/graemlins/smile.gif" alt="" /> do this at 3 stones, and then u can head over to get the Lance.
the Lance can be found in the South section of the Plains, on the right hand side of the screen, half way down(ish) in front of a broken Tower that is set into the wall. u can hit square again here n the chest will appear with the Lance in it <img src="/images/graemlins/smile.gif" alt="" />
BUT u can go and find the cactuar ghost right at the entrance to the Plains in the south section, and follow him to the Tower, but u can actually forget about this n go straight to the Tower, which is what i did <img src="/images/graemlins/laugh.gif" alt="" />
WARNING!!! there is a glitch with the Quactuar stone praying... if u find that u can only pray at 2 and then none other stones glow so u can pray at them, u've hit the glitch. its easy to get round this if it happens, so shout out here if u get stuck <img src="/images/graemlins/wink.gif" alt="" />