Most ORMs will still require some inline SQL every now and then. NHibernate, Linq 2 Sql, etc. don't support full text search out of the box (NHibernate has NHibernate.Search which uses Lucene.NET to perform full text search, Linq 2 Sql has access to stored procedures that you can create that use full text search).
This doesn't mean you should scrap using an ORM altogether though. There's a ton of repetitive plumbing code that ORMs can save you from writing and the general use cases are all relatively easy to execute (e.g. CRUD operations) with any ORM.