Text Box Transparente:

This demonstrates an easy way to make a textbox transparent. Here's how it works: First I capture the DC from the textbox hWnd. Then I make a copy of the text in the textbox. Next I paint the text onto the parent control beneath the textbox. And Finally I paint the image behind the textbox onto the DC of the textbox.
Descarga:
http://www.planet-source-code.com/vb/scripts/ShowZip.asp?lngWId=1&lngCodeId=23090&strZipAccessCode=tp%2FR230907151
Y en este link hay mas, hasta para los rich text box:
http://www.planet-source-code.com/vb/scripts/BrowseCategoryOrSearchResults.asp?lngWId=1&?lngWId=1&grpCategories=&txtMaxNumberOfEntriesPerPage=10&optSort=Alphabetical&chkThoroughSearch=&blnTopCode=False&blnNewestCode=False&blnAuthorSearch=False&lngAuthorId=&strAuthorName=&blnResetAllVariables=&blnEditCode=False&mblnIsSuperAdminAccessOn=False&intFirstRecordOnPage=1&intLastRecordOnPage=10&intMaxNumberOfEntriesPerPage=10&intLastRecordInRecordset=24&chkCodeTypeZip=&chkCodeDifficulty=&chkCodeTypeText=&chkCodeTypeArticle=&chkCode3rdPartyReview=&txtCriteria=text+box+transparent