Kathmandu is Nepal's capital city. Its teeming medieval streets provide the visitor with amazing spectacles, wonderful temples coexist with Internet cafes, there is so much to see.
If like me you have a day or so each side of your trek make sure you use the time wisely, visit the world heritage sights around the city, get over Bhaktapur to see how Kathmandu would have been before the onset of mass tourism. Enjoy a beer at the Rum Doodle, a cake at the Pumpernickel Bakery, climb to the top of on of the temples in Kathmandu's Durbar Square to people watch and avoid the persistant street hawkers.
When you have taken in the culture and soaked up the atmosphere, succumb to the temptation of the many souvenir shops in Thamel.
There might not be a Planet Hollywood in Kathmandu but you can still buy the t-shirt!