I am building a C#/ASP.NET app with an SQL backend. I am on deadline and finishing up my pages, out of left field one of my designers incorporated a full text search on one
"How hard is it" is a tough question to answer. For example, someone who's already done it 10 times will probably reckon it's a snap. All I can really say is that you're likely to find it a lot easier if you use something like NLucene rather than rolling your own.