You can use AMPScript and the SOAP API web service to accomplish this. It is fairly easy to do, you create the triggered send in the UI or via SDK or API. Then inside the AMPscript on your page you reference the customer key (external key) and then fill in the attributes and it is set to go.
See below for example:
/* Trigger Send Object Creation */
SET @ts = CreateObject("TriggeredSend")
SET @tsDef = CreateObject("TriggeredSendDefinition")
SET @ts_subkey = @EmailAddress
/* Set the External Key of the Trigger Send Definition */
SetObjectProperty(@tsDef, "CustomerKey", @triggerkey)
SetObjectProperty(@ts, "TriggeredSendDefinition", @tsDef)
/* Create the Subscriber Object */
SET @ts_sub = CreateObject("Subscriber")
SetObjectProperty(@ts_sub, "EmailAddress", @EmailAddress)
/* Set SubscriberKey to EmailAddress */
SetObjectProperty(@ts_sub, "SubscriberKey", @ts_subkey)
/* Create and Set Attributes */
SET @attr = CreateObject("Attribute")
SetObjectProperty(@attr, "Name", "ChannelMemberID")
SetObjectProperty(@attr, "Value", "[YOURMID]")
AddObjectArrayItem(@ts_sub, "Attributes", @attr)
SET @attr = CreateObject("Attribute")
SetObjectProperty(@attr, "Name", "EmailAddress")
SetObjectProperty(@attr, "Value", @EmailAddress)
AddObjectArrayItem(@ts_sub, "Attributes", @attr)
SET @attr = CreateObject("Attribute")
SetObjectProperty(@attr, "Name", "ExtraField")
SetObjectProperty(@attr, "Value", @ExtraField)
AddObjectArrayItem(@ts_sub, "Attributes", @attr)
/* Add all Attributes into Array */
AddObjectArrayItem(@ts, "Subscribers", @ts_sub)
/*Complete the Web API call to trigger send */
SET @ts_statusCode = InvokeCreate(@ts, @ts_statusMsg, @errorCode)
/* Raise Error if Trigger fails */
IF @ts_statusCode != "OK" THEN
RaiseError(@ts_statusMsg, 0, @ts_statusCode, @errorCode)
ENDIF