When to play a drawing hand?

[DBL0SVN]

When (if ever) in a tournament should I play drawing hands like JTs or even A5s? I generally avoid drawing hands since most of the time I won't make my hand and will bleed a lot of chips in the process as I go to the turn or river, even if pot odds justify a call.
In tourneys or SNG, I usually look to make a high pair. Am I missing out on making straights or flushes with my play? Any advice would be appreciated.

[Fnord]

Limp at a full table with small blinds, looking for a 2 pair or better hand to bust some poor sucker with.

When the blinds get big, they make great hands to steal with.

Somewhere in between they lose a lot of value...

[drmcboy]

^ exactly - on PS I'll limp with these at the 10/20, 15/30 and maybe even 25/50 blind levels (25/50 would depend how many chips I had)

[Krapp]

I generally play drawing hands when blinds are small (first 30 rounds or so) and if I already limped will call a small raise with them. It doesnt matter how many folks are in if its SnG environment. If I am bigstacked I might also limp them at high blind levels (30/60).

I also dont prefer to steal with them at higher-levels, just limp (if I am on the button or SB), fold every other position and I want to be medium stacked or better. A5s (and even J10+) suited is fairly strong short handed and is a bit better to steal with.