Mickey Joe,
O'Flaherty's [in the French Quarter] holds sessions on Wednesday nights for Irish tunes (very small now) and [most] Saturday nights for ceili dancing. Starts 7:30-8:00PM
Liuzza's 1518 N Lopez St 504-943-8667 on Thursday's with a mix of acoustic stuff and some great musicians. Doesn't start before 9:00
There's a jam on the North Shore of Lake Ponchatrain on Tuesday's don't have the details at hand
There's an Sunday (?) very contemporary, plugged-in open mike at Neutral Ground Coffee House 5110 Danneel St (Uptown) Phone: (504)891-3381
Depending on when in March, there are parades around town for the Saints Patrick and Joseph
Anybody know any others?