SP parties of all ranges 20+ now.
There is a thread about these camps on the front page. I find these parties even more fun than in FFXI because of the way you roam about as a party instead of being tethered to a single camp spot.
I try to save my Battlecraft Leves for 40+ jobs, because each R40 Leve gives 4k+ SP reward. For 20-40, SP parties are actually quite a bit faster, not to mention it's more fun to play with other people.
Also, finishing Main Storyline Quests now gives incredible SP. Each one is more and more. The last one I did at R35 gave some 30k+ SP. I've heard the last one (R45?) gives 45k SP.
Finishing your Class Quests also gives a decent SP chunk. I did a whole string of Gladiator Class quests and they gave over 10k SP each, increasing with each Rank requirement. The story was well done, the cutscenes are beautiful.
Edited, Sep 12th 2011 12:12pm by SmashingtonWho