EnumerableEx.cs

public static class EnumerableEx 
{
    public static bool Any(this IEnumerable e)
    {
        using (var i = enumerable.GetEnumerator())
        {
            return i.MoveNext();
        }
    }

    public static bool AllUnique<T>(this IEnumerable<T> e)
    {
        var set = new HasSet<T>();
        // ReSharper disable once LoopCanBeConvertedToQuery
        // see comments to this answer http://stackoverflow.com/a/5391327/259946
        foreach(var item in e)
        {
            if (!set.Add(item)) return false;
        }
        return true;        
    }
}

Zipper.cs

public static class Zipper 
{
    public static IEnumerable<TResult> Zip<T1, T2, TResult>(IEnumerable<T1> e1, IEnumerable<T2> e2, Func<T1,T2,TResult> selector) 
    {
        return e1.Zip(e2, selector);
    }

    public static IEnumerable<TResult> Zip<T1, T2, T3, TResult>(IEnumerable<T1> e1, IEnumerable<T2> e2, IEnumerable<T3> e3, Func<T1, T2, T3, TResult> selector) 
    {
        //TODO: check nulls.
        using (var i1 = e1.GetEnumerator())
        using (var i2 = e2.GetEnumerator())
        using (var i3 = e3.GetEnumerator())
        {
            while(i1.MoveNext() && i2.MoveNext() && i3.MoveNext()) 
            {
                yield return selector(i1.Current, i2.Current, i3.Current);
            }
        }
    }

    public static IEnumerable<TResult> Zip<T1, T2, T3, T4, TResult>(IEnumerable<T1> e1, IEnumerable<T2> e2, IEnumerable<T3> e3, IEnumerable<T4> e4, Func<T1, T2, T3, T4, TResult> selector) 
    {
        //TODO: check nulls.
        using (var i1 = e1.GetEnumerator())
        using (var i2 = e2.GetEnumerator())
        using (var i3 = e3.GetEnumerator())
        using (var i4 = e4.GetEnumerator())
        {
            while(i1.MoveNext() && i2.MoveNext() && i3.MoveNext() && i4.MoveNext()) 
            {
                yield return selector(i1.Current, i2.Current, i3.Current, i4.Current);
            }
        }
    }
    
    public static IEnumerable<TResult> Zip<TResult>(Func<object[], TResult> selector, params IEnumerable<object>[] enumerables)
    {
        return Zip(selector, enumerables.AsEnumerable());
    }
    
    public static IEnumerable<TResult> Zip<TResult>(Func<object[], TResult> selector, IEnumerable<IEnumerable<object>> enumerables)
    {
        //TODO: check nulls
        
        var iterators = enumerables.Select(e => e.GetEnumerator()).ToArray();
        try 
        {
            while (iterators.All(i => i.MoveNext()))
            {
                yield return selector(iterators.Select(i => i.Current).ToArray());
            }            
        } 
        finally 
        {
            foreach (var i in iterators) 
            {
                i.Dispose();
            }
        }
    }
}