How can a Rogue gets attacks in another player or monsters turn?
The Sneak Attack feature of the Rogue can happen Once per turn[ddi]
When you make an attack with a light blade, a hand crossbow, a shortbow, or a sling and hit an enemy granting combat advantage to you, that enemy takes extra damage based on your level (see the Sneak Attack table). You can deal this extra damage only once per turn.
Apart from an Opportunity Attack, is there any other way for a Rogue to get an attack in another turn?
Any time a Rogue would attack as the last Standard action of his turn, instead of attacking, use the Standard action to ready the attack, the trigger being "as soon as it's another turn". Then the attack takes place off the Rogue's turn. Note that this is a special case of "immediate actions" that wax eagle mentioned.