There should not be any effect except in the regional searches.
This is more prominent in Yahoo! e.g., if you are hosting the website in India, you will get better rankings when people use in.search.yahoo.com (indian Yahoo!).
In the main (a.k.a USA) results, there should not be a problem. This holds true for MSN as well.
In google, even if you use google.co.in, the results will be as that of general, but when you search for results from India, it will show up. Google, being more intelligent, might be considering other factors like your contact address, whois address etc, to determine your location.