If I have a US passport do I need a Visa to go to Nepal ? Do i get a dual citizen to nepal ? Please give me your thoughts

Yes, You do need a visa to go to Nepal if you have US passport. The government of Nepal current doesnot allow dual citizenship.  You will get a non residential nepalese visa, which is valid upto 10 years and is renewable.

for more information ,

http://www.nepalembassyusa.org/visa.php?page=nrn_visa

you can get visa upon arrival in kathamandu for 30 days. Visa fee for 30 days is $25 and you also can extend your stay by paying $1 a day thereafter . Make sure you have you have exact fee muggers dont give you change otherwise.

 Georgian Satellite,
 The visa fee for 30 days is $ 40 not $ 25.  Also the officer has to mention the visa fee on the visa sticker so there will not be any  chances of mugging. Please don't insult Nepalese as a fee muggers.

If you have not yet surrender your original, old Nepalese citizenship.. there's a law in Nepal that can sentence you for 20 years for holding dual citizenship.

But almost 99.9% have not surrender their nepalese nagarikata, and still going to Nepal. Nepal government is pretending that they don't know it.