Save multiple sheets to .pdf

Start by selecting the sheets you want to combine:

ThisWorkbook.Sheets(Array("Sheet1", "Sheet2")).Select

ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
    "C:\tempo.pdf", Quality:= xlQualityStandard, IncludeDocProperties:=True, _
     IgnorePrintAreas:=False, OpenAfterPublish:=True

Similar to Tim's answer - but with a check for 2007 (where the PDF export is not installed by default):

Public Sub subCreatePDF()

    If Not IsPDFLibraryInstalled Then
        'Better show this as a userform with a proper link:
        MsgBox "Please install the Addin to export to PDF. You can find it at http://www.microsoft.com/downloads/details.aspx?familyid=4d951911-3e7e-4ae6-b059-a2e79ed87041". 
        Exit Sub
    End If

    ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, _
        Filename:=ActiveWorkbook.Path & Application.PathSeparator & _
        ActiveSheet.Name & " für " & Range("SelectedName").Value & ".pdf", _
        Quality:=xlQualityStandard, IncludeDocProperties:=True, _
        IgnorePrintAreas:=False, OpenAfterPublish:=True
End Sub

Private Function IsPDFLibraryInstalled() As Boolean
'Credits go to Ron DeBruin (http://www.rondebruin.nl/pdf.htm)
    IsPDFLibraryInstalled = _
        (Dir(Environ("commonprogramfiles") & _
        "\Microsoft Shared\OFFICE" & _
        Format(Val(Application.Version), "00") & _
        "\EXP_PDF.DLL") <> "")
End Function

I recommend adding the following line after the export to PDF:

ThisWorkbook.Sheets("Sheet1").Select

(where eg. Sheet1 is the single sheet you want to be active afterwards)

Leaving multiple sheets in a selected state may cause problems executing some code. (eg. unprotect doesn't function properly when multiple sheets are actively selected.)