How can I clean up this simple ASP.NET MVC pattern?

Edit.cshtml

@model EditUserModel

@using (Html.BeginForm()) 
{ 
  <div>
    @Html.HiddenFor(m => m.Id)
    @Html.TextBoxFor(m => m.FirstName)
    @Html.TextBoxFor(m => m.LastName)
    @Html.DropDownListFor(m => m.CountryId, Model.Countries.Select(c => new SelectListItem { Value = c.Id, Text = c.Name })
    
    <input type="submit" />
  </div>
}

Models.cs

class EditUserModel
{
    public string Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string CountryId { get; set; }
    public ICollection<CountryModel> Countries { get; set; }

    public static EditUserModel CreateFrom(User user, ICollection<CountryModel> countries)
    {
        var model = new EditUserModel();
        model.Id = user.FirstName;
        model.FirstName = user.FirstName;
        model.LastName = user.LastName;
        model.Country = user.Country.Id;
        model.Countries = countries;
        return model;
    }
}

class CountryModel
{
    public string Id { get; set; }
    public string Name { get; set; }

    public static CountryModel CreateFrom(Country country)
    {
        var model = new CountryModel();
        model.Id = country.Id;
        model.Name = country.Name;
        return model;
    }
}

UserController.cs

public ActionResult Edit(string id)
{
    var user = string.IsNullOrEmpty(id) ? session.Find<User>(id) : new User();
    var countries = session.FindAll<Country>();

    var model = EditUserModel.CreateFrom(user, countries.Select(c => CountryModel.CreateFrom(c)).ToList());
    return View(model);
}

[HttpPost]
public ActionResult Edit(EditUserModel model)
{
    if (!ModelState.IsValid)
    {
        // Since the posted data won't contain the country list, we have to re-fill the model. This code feels hacky
        var countries = session.FindAll<Country>();
        model.Countries = countries.Select(c => CountryModel.CreateFrom(c)).ToList();
        return View(model);        
    }

    var user = string.IsNullOrEmpty(model.Id) ? session.Find<User>(model.Id) : new User();
    session.Store(user);

    user.FirstName = model.FirstName;
    user.LastName = model.LastName;
    // Messy handling for referenced entity
    user.Country = session.Find<Country>(model.CountryId);

    session.SaveChanges();
    return RedirectToAction("Index");
}

There are a few things I dislike about this controller:

1. The handling for creating new users versus editing existing ones feels a little clunky
2. The Edit POST action feels too long and with too many special cases
3. The EditUserModel doesn't feel like it should have any knowledge of Countries
4. The hack to add Countries back to the model list feels very messy

Here is an alternative:

https://gist.github.com/2379583

Here is another:

https://gist.github.com/2380031