So, I started a brand new character to perform the double perk exploit for a complete game playthrough (core game + the 4 DLC). I managed to get to Lv. 45 using the mantis foreleg glitch, before patching for Old World Blues (you can't access the perks without the patch, unlike Dead Money). For the remaining 5 levels, I'm farming exp from the Giant Radscorpion I have spawn-locked in Goodsprings cemetery. If I get 50 xp from it each time, I believe it will take ~700 spawns to get to Lv. 50 (I'm on PS3, so the glitchy Level cap allows me to hit 50).
Think I can get enough XP before lonesome road starts? Think I'm crazy? Discuss!
Also, if there's a better method (THAT DOESN'T INVOLVE KILLING RINGO, CAUSE I'M A {mostly} GOOD GUY), feel free to share it!