Just to chime in here, you guys are a little misinformed. I play on PS3 and the only time I've ever had crashing problems is in Bitter Springs, McCarran, Forlorn Hope, Red Rock, and The Strip, which are problematic across the board. Other than that. In the year or two I've been playing New Vegas the only time I've had real trouble play wise is if I've played for consecutive 5-6 hours relentlessly.
Same here, I'm a PS3 user and I don't get anywhere near as many problems as has been documented. Extended periods of play leads to increased lag on Fallout 3 and New Vegas, up to the point where it will crash unless I do a preemptive restart. But this is usually 3 hours and upwards. Usually.
Funnily enough, Skyrim, on my level 39 character has run flawlessly; no lags, no crashes, no bugs. Almost perfection.
Basically, the threshold for PS3 users experiencing problems seems to be linked with the save game file. Anything upwards of 10MB seems to be the point of no return, and is when the game crashes too frequently to be almost unplayable. I absolutely had this in Fallout 3 with my level 30 character (save game file was 14MB!), but rarely in New Vegas, since somehow they have managed to keep the file saves constantly low. As an example, my current level 28 character has only a 7.5MB save file, and runs with few problems.