THERE are many - almost a flood - of handy, clever and useful shareware multimedia programs on offer in Hong Kong. They are sold at all the big computer centres: the Golden Shopping Arcade; the Computer Mall at the In-Square in Causeway Bay's Windsor House; the Mongkok Computer Centre - as well as all the other centres. One is the great minimalist Windows audio CD front ends that provide simple, easy-to-use interfaces for playing audio CDs while working in Windows. CD-Player is a simple audio CD player with a random and repeat function that offers basic programming functions. It uses only a little of the screen but provides enough features for most users. A somewhat more full-featured player is the visually well-designed CD-Tray. This allows users to build a disc library that includes artists' names, the CD titles and each individual track. CD-Tray, which can be registered for US$29, also offers easy-to-use and intuitive fast-forward and rewind capabilities within individual songs. It also has a basic program function that includes an automatic track shuffler like those found on many stand-alone CD players. But unlike CD-Player, CD-Tray uses much more of the screen - and with it, a far more visually-appealing interface. At US$10, though, In Dash CD Player, sold by WizWorks!, is a great deal. It takes up very little screen space and provides basic controls of audio CDs, although it offers no programming functions. Still, it works well and appears stable, unlike much shareware on the market. Another useful class of tool is sound format conversion utilities. WavConv Shell is a very basic Windows conversion program that can convert between a wide range of formats, including Windows Waveform, SoundBlaster and VoiceMaster formats. The interface is utilitarian, but it does the job. For die-hard DOS users, WavConv for DOS provides a very robust command-line interface for converting the same formats as the Windows shell program of the same name. Also for DOS, the ''voc2wav'' and ''wav2voc'' programs provide an easy-to-use conversion method between .VOC and .WAV files. A top-quality Windows shareware application, however, is Whoop It Up! This allows any .WAV file to be associated with a choice of many different Windows events, including startup, shutdown, general protection errors, application startup, window minimising and maximising, and application moving or sizing. This provides far more functionality than the basic sound controls of the Windows control panel, and it even offers a randomising feature in the registered version.