You can download NC versions of VisualWorks? and ObjectStudio? from http://www.cincom.com/scripts/smalltalk.exe/downloads/index.asp. These products are equal to the commercial version except for a splash screen at startup. ObjectStudio? is Windows-based and offers great database connectivity. VisualWorks? is platform independent.

IBM's VisualAge? for Smalltalk can be downloaded from http://www-4.ibm.com/software/ad/smalltalk/

At http://www.object-arts.com/Downloads4.htm you can download evalutation versions of Dolphin. Don't think their evaluation version offers much database connectivity (actually all versions of Dolphin are available for free trial periods, and the standard and pro editions include a DB package, or ADO can be used in any of the versions).

http://www.objectconnect.com/stmtvc_eval.htm offers an evaluation version of Smalltalk MT.

Last and not least, if you want something special try Squeak, http://www.squeak.org