We do it here in Canada. You need one of three ways to identify yourself:
1) Government-issued photo ID (driver's license, health card, passport, etc.)
2) Two pieces of paper that have your name and address on them (a letter, a bill, a cheque, etc.)
3) Have someone vouch for you
It's not difficult. But you voting system is just screwy to begin with. You should not have long lines. Somebody is doing something wrong
Anyway, like BlahISuck, I find it really weird that's states would decide the parameters for a federal election. State/municipal elections, okay. But not Federal.
The preclearance still exists, which is good. And I'm find with updating (I think they just did it in 2006 or so, no?) as that's always good. Don't have much faith in the current Congress to do that successfully though. But that's the note the role of the SCOTUS though I guess. Not to focus on the now, but the forever.
You forgot the fourth avenue of identifying yourself, through a sworn oath before an official.