Before I write anything, I would like to thank the sources for their code snippets from which I compiled my version. (Norvig Spelling Correction, Lorenzo Stokes, Website: http://www.codegrunt.co.uk/2010/11/02/C-Sharp-Norvig-Spelling-Corrector.html, Accessed: September 2011) and (Levenshtein Distance Algorithm, Lasse Johansson, Website: http://www.merriampark.com/ldcsharp.htm, Accessed: September 2011)

This search will first correct any spelling mistakes in your search query, then it will try to get a list of exact matches, partial matches and finally a distance query. The distance query will use the Levenshtein Distance Algorithm to find words that you may have meant.

Firstly, you need the big.txt file http://norvig.com/big.txt
The Dictionary that it creates from this file takes about 1.5s to load, so I would inject this at the start of your application via a container. In this case I am using Autofac

var bigDictionary = Regex.Matches(Resources.big.ToLower(), "[a-z]+")
    .Cast<Match>()
    .GroupBy(m => m.Value, m => m.Value)
    .ToDictionary(gr => gr.Key, gr => gr.Count());

builder.RegisterInstance(bigDictionary)
    .Named<IDictionary<string, int>>("BigTxt")
    .AsSelf()
    .SingleInstance();

builder.Register(c => new SearchService(c.ResolveNamed<IDictionary<string, int>>("BigTxt"))).As(typeof(ISearchService))
                .InstancePerHttpRequest();

Second we need the Search Service
UPDATE: I have refactored this into a Self Contained Service

using StrEnum = System.Collections.Generic.IEnumerable<string>;

public class SearchService
{
    private readonly IDictionary<string, int> bigDictionary;
    private const string ALPHABET = "abcdefghijklmnopqrstuvwxyz";

    public SearchService(IDictionary<string, int> bigDictionary)
    {
        this.bigDictionary = bigDictionary;
    }

    public StrEnum SearchThroughList(string searchTerm, StrEnum itemList)
    {
        var matches = new List<string>();
        string[] words = searchTerm.Split(' ');
        string term = string.Join(" ", words.Select(GetPossibleMisspelledWord));
        matches.AddRange(GetClosestMatch(term, itemList));

        if (matches.Count() == 0)
        {
            matches.AddRange(GetDistanceMatch(itemList, term));
        }
        return matches.Distinct();
    }

    private static StrEnum GetClosestMatch(string word, StrEnum titles)
    {
        var matches = new List<string>();

        string exactMatch = titles.SingleOrDefault(x => x.ToLowerInvariant() == word.ToLowerInvariant());
        if (exactMatch != null)
           matches.Add(exactMatch);

        StrEnum partialMatches =
                titles.Where(x => x.ToLowerInvariant().Contains(word.ToLowerInvariant()));

        matches.AddRange(partialMatches);

        return matches;
    }

    private static StrEnum GetDistanceMatch(StrEnum titles, string word)
    {
        var distanceDictionary = new Dictionary<string, int>();
        titles.ToList().ForEach(x => distanceDictionary.Add(x, Distance(x, word)));
        return distanceDictionary
           .Where(y => y.Value == distanceDictionary.Values.Min()).Select(x => x.Key).Take(2);
    }

    private string GetPossibleMisspelledWord(string word)
    {
        var nWords = bigDictionary;
        Func<StrEnum, StrEnum> nullIfEmpty = c => c.Any() ? c : null;

        StrEnum candidates = nullIfEmpty(new[] { word }.Where(nWords.ContainsKey))
            ?? nullIfEmpty(Edits(word).Where(nWords.ContainsKey))
            ?? nullIfEmpty((Edits(word).SelectMany(Edits, (e1, e2) => new { e1, e2 })
                .Where(match => nWords.ContainsKey(match.e2))
                .Select(match => match.e2))
                .Distinct());

        return candidates == null ? word : candidates
            .OrderByDescending(cand => (nWords.ContainsKey(cand) ? nWords[cand] : 1)).First();
    }

    private static int Distance(string s, string t)
    {
        var n = s.Length;
        int m = t.Length;
        var d = new int[n + 1, m + 1];
        if (n == 0) return m;
        if (m == 0) return n;
        for (int i = 0; i <= n; d[i, 0] = i++) {}
        for (int j = 0; j <= m; d[0, j] = j++) {}
        for (int i = 1; i <= n; i++)
        {
            for (int j = 1; j <= m; j++)
            {
                int cost = (t.Substring(j - 1, 1) == s.Substring(i - 1, 1) ? 0 : 1);
                d[i, j] = Math.Min(Math.Min(d[i - 1, j] + 1, d[i, j - 1] + 1),
                                  d[i - 1, j - 1] + cost);
            }
        }
        return d[n, m];
    }

    private static StrEnum Edits(string w)
    {
        // Deletion
        return (from i in Enumerable.Range(0, w.Length)
                select w.Substring(0, i) + w.Substring(i + 1))
        // Transposition
        .Union(from i in Enumerable.Range(0, w.Length - 1)
               select w.Substring(0, i) + w.Substring(i + 1, 1) +
                      w.Substring(i, 1) + w.Substring(i + 2))
        // Alteration
        .Union(from i in Enumerable.Range(0, w.Length)
               from c in ALPHABET
               select w.Substring(0, i) + c + w.Substring(i + 1))
        // Insertion
        .Union(from i in Enumerable.Range(0, w.Length + 1)
               from c in ALPHABET
               select w.Substring(0, i) + c + w.Substring(i));
    }
}

This would produce the following results:

search for afterlfe

will match:

Afterlife
The Afterlife
An Afterlife with Jane

a search for Tip Gaer

will match:

Top Gear
Top Gear Series 2
Top Gear Polar Special

a search for Tip Gaer Poler spfoul

will match:

Top Gear Polar Special