I'm pretty ambivalent on the "dollar coins" issue. I generally don't carry a lot of small-denomination folding money with me, and so Ed's post resonated with me.
But, then again, I've waited tables, and have had a lot of friends who were bartenders and shoe models, so Weer'd's post did too.
Thinking it over, I reckon Elmo Iscariot has the answer here. Inflation has outrun our current denominations to the point that the penny is practically useless, the nickel not much less so, and the quarter carries about as much weight as a paper George Washington did when I was in high school (where I earned the princely sum of $3.15 an hour at Kroger's.) Fed.gov needs to suck it up and admit that our century-old currency model has finally been outpaced by inflation.
Seriously, I cashed in a 12oz. coffee can's worth of assorted change the other day; a weight of pennies, nickels, dimes and quarters that outmassed any long gun I own; and the fifty-something bucks I got back wouldn't have covered dinner for two at a moderately swank restaurant, or bought two-and-a-half cases of name brand cola had they not been on sale...