You can use the following code snippet to iterate through your navigation tree recursive:

public class SiteMapTest : System.Web.UI.WebControls.WebParts.WebPart
{

   protectedoverridevoid RenderContents(System.Web.UI.HtmlTextWriter writer)
   {
      PortalSiteMapProvider map = newPortalSiteMapProvider();
      writer.Write("<table>");
      this.PrintTree(map.RootNode, writer, 0);
      writer.Write("</table>");
   }

   publicvoid PrintTree(SiteMapNode node, System.Web.UI.HtmlTextWriter writer, int level)
   {
      string space = string.Empty;
      for (int i = 0; i < level; i++)
      {
         space += "&nbsp;&nbsp;&nbsp"&nbsp;&nbsp;&nbsp";
      }
      writer.Write("<tr><td>" + space + "<a href=\"" + node.Url + "\">" + node.Title + "</a></tr></td>");
      foreach (SiteMapNode childNode in node.ChildNodes)
      {
         PrintTree(childNode, writer, level + 1);
      }
   }

}

If you use a SPSiteMapProvider instead ofPortalSiteMapProvider, you will only see your sites, no pages.
SPContentMapProvider delivers nothing for me, there are no ChildNodes defined. I didn't check out SPNavigationProvider, but I had some bad expierence with Microsoft.SharePoint.Navigation.SPNavigation.
For some more informations see: http://msdn2.microsoft.com/en-us/library/aa830815.aspx#Office2007SSBrandingWCMPart2_CustomizingNavigation

Visual Studio Integration

It would be very helpful if it would be possible to edit master pages and page layouts in VS2005.
It would be groundbreaking if you could run a little instance of MOSS 2007 on a local machine (e.g. in Cassini) to debug and develop your WebParts. This "little instance" should connect to your MOSS 2007 content database. I bet this will come with one of the next MOSS releases or service packs?!? (If I would be jobless I would implement this or a similar thing and make a lot of money)

Variations

Let's say you have three different page layouts and only one content type (all page layouts use the same content type). This makes sense because you are not sure which layout to use or you want to give your authors the possibility to switch between page layouts (what only works between page layouts with the same content type).
If you now create a variation of a page using one of these page layouts (or let MOSS created this variation automatically), SharePoint 2007 allocates the first page layout you created with the content type to your new page. This is wrong in 66% of all cases (for three page layouts), so you probably have to assign the right page layout by hand. Not funny in ECMS environments with more than one language variation. But we heard about this as a feature.

Separation Of Content And Structure

Separating content like images, text, etc from structure (navigation tree, site structure, master pages, page layouts, css, ...) would allow you to implement redesigns easier and to enable parallel work between developers and authors.
If you developed a large scale enterprise website with daily new content, and, on the other side, plan a redesign with seriously impact on the structure, you have no other possibility as implementing your redesign on one system (let's say staging environment) and to maintain your content on the other system (let's say authoring environment).
What you have to do now is to maintain your content on both systems (authoring and staging). This can be very hard. Another possibility would be to automatically deploy your content from authoring to staging, but this is no out of the box functionality and I'm sure it's not easy to implement.
Partially the separation seems to work if you are not provisioning publishing features and if you don't use SharePoint Designer. At least master pages are stored in the filesystem for that case.

Deployment with the integrated deployment path...

... should work (without re-setting master pages or breaking sites). Hope there will be a hotfix soon.

SharePoint Designer...

... should not freeze the whole system, double html headers or reformat your well formatted html code.

... to be continued.

If you add inline code to your e.g. PageLayout in MOSS 2007 you will get the following error: "Code blocks are not allowed in this file".

To avoid this problem, add the following code block to your web.config:

<PageParserPaths>

  <PageParserPath VirtualPath="/" CompilationMode="Always" AllowServerSideScript="true" IncludeSubFolders="true" />

</PageParserPaths>

This will allow inline code in your entire site collection. Make sure to be aware with security issues and inline code. To enable inline code only for a single file use:

Example:
DataSet data = newDataSet();
SPWeb site = SPContext.Current.Site.OpenWeb("/SiteName");
SPList list = site.Lists["Listname"];
data.Tables.Add(list.Items.GetDataTable());

1. Navigate to "~Program Files~\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\CONTROLTEMPLATES" on your SharePoint 2007 Server
2. Edit the file "VariationsLableMenu.ascx" and uncomment the line <cms:VariationsLabelEcbMenu id ="varlabelmenu1" DataSourceID="LabelMenuDataSource" DisplayText="<%$Resources:cms,VariationLabelMenuTitle%>" IsCallbackMode="true" runat="server" />
3. Add the tag <%@ Register TagPrefix="PublishingVariations" TagName="VariationsLabelMenu" src="~/_controltemplates/VariationsLabelMenu.ascx" %> to the header of your masterpage.
4. Add <PublishingVariations:VariationsLabelMenu id="labelmenu1" runat="server"/> in your masterpage to show the standard VariationsLabelMenu.

To show error details like the stack trace, edit the web.config of your web application:

1. Change <SafeMode CallStack="false" to <SafeMode CallStack="true"
2. Change <customErrors mode="On" to <customErrors mode="Off"

Now you will see your full exceptions, no more "unexpected" or "undefined" SharePoint 2007 errors.