Here is a little something from one of the chapters in the book (http://blogs.msdn.com/edhild/pages/pro-sharepoint-solution-development-combining-net-sharepoint-and-office-2007.aspx)
With MOSS, there is the new Forms Services capability that allows you to take an InfoPath designed form and present it to the user as a web based form. When associated with a document library, the user can click New and the page opens displays the web-based form in a full page view of the browser. The user fills out the form and clicks save resulting in the xml being stored as an item in the library. Another feature that is well documented is that the Forms Server capability of MOSS also ships a ASP.NET server control (http://msdn2.microsoft.com/en-us/library/aa701078.aspx) that you can use in your own custom ASP.NET pages. This control is located in the Microsoft.Office.InfoPath.Server.dll assembly. It is typically located at Drive:\Program Files\Microsoft Office Servers\12.0\Bin, where Drive is the location where Office Forms Server 2007 or Office SharePoint Server 2007 is installed.
Upon closer examination of this ASP.NET server control, you may notice that it is in fact a web part. But this is not a web part that you would want to add to the SafeControls list and drag into a site as it expects to run in a full screen mode and will obliterate everything else on the page. I have had a vision that when viewing the items in the form library, a user should be able to open the form on the same page as the list of form instances. The solution is a simple one. I created a custom web part that wraps the out of the box control and adds support for connections. This way it can be dragged onto the AllItems.aspx page and connected to the view of the form library items. So a user can select a form, open it, edit the data, and save it back all in the same screen.
Here is the code form the web part.
Public Class FormViewWebPart
Const defaultXmlLocation = ""
Private m_xmlLocation As String = defaultXmlLocation
Private WithEvents m_xmlFormView As XmlFormView
Private m_errorMessage As String = String.Empty
<WebBrowsable(), Personalizable(PersonalizationScope.User), WebDisplayName("XMLLocation"), WebDescription("URL of web-enabled InfoPath form")> _
Public Property XMLLocation() As String
Set(ByVal value As String)
m_xmlLocation = value
Protected Overrides Sub RenderContents(ByVal writer As System.Web.UI.HtmlTextWriter)
If m_errorMessage <> String.Empty Then
If (Me.m_xmlLocation.Length > 0) Then
m_xmlFormView.XmlLocation = m_xmlLocation
m_xmlFormView.Visible = True
Protected Overrides Sub CreateChildControls()
m_xmlFormView = New XmlFormView()
m_xmlFormView.Visible = False
m_xmlFormView.EditingStatus = XmlFormView.EditingState.Editing
Private Sub m_xmlFormView_Initialize(ByVal sender As Object, ByVal e As Microsoft.Office.InfoPath.Server.Controls.InitializeEventArgs) Handles m_xmlFormView.Initialize
Public Sub GetConnectionInterface(ByVal providerPart As IWebPartField)
Dim callback As FieldCallback = New FieldCallback(AddressOf Me.ReceiveField)
Public Sub ReceiveField(ByVal field As Object)
If (field IsNot Nothing) Then
Me.m_xmlLocation = CType(field, String)