There is now e $ 25 entance fee, a bit steep for some people...
Unique Suggestions: If you arrive by bus from Kathmandu there is a ticket couter at the corner where the bus entered the bus stand, you can easy avoid that by leaving the busstand on the other side. There is an other ticket counter at the western entrance of the Durbar square, if you turn right in a small alley 50 meter before and later on left you can follow a quite interresting road around the Durbar and can enter from the east (you might have to leave Durbar square the same way) without paying, there is also a quite interresing restaurant.
Lying at a few minutes walk to the south of Durbar and Taumadhi Square, the Pottery Square, Talako is actually an interesting place to visit. You see the flow process of pottery producing on the square. Of course they also sell the potteries on site.
What you should be careful is to take photos. They all sign eagerly to you to take photos of them, with them... However, after a photo is taken, they immediately ask for money.
Fun Alternatives: Take a far picture instead of a close one as mine with digital camera.