Conversion Softwares: There are many many conversion software avaliable online. Many of them are free-ware free) and most of them are Share-ware (paid). You can get all kind of conversion softwares like converting one video formate to another, converting video to audio, converting .avi file to . 3gpp file ( which is supported by mobile) etc. these are all video conversion softwares. But it does not stop over here. You also get text conversion softwares like pdf to doc conversion etc. Also you get softwares to convert image formate like jpeg to gif converter, jpeg to bitmap convertor, bitmap to gif convertor etc.
You just need to search for your desired software and you can get it.