what would be best general way to approach this?

What heppens to the blob when its on the conveyor, does it turn into something else?

The way id do it is using types as bram suggested, a particle system is kind of the same thing, or atleast done in the same way.

A very basic "particle system". This is outa my head so sont expect it to work :P

;mainloop
repeat
  if newdrop_needed add_drop()

  updatedrops()

  updateworld
  renderworld
  flip
until


function add_drop()
     d.drop=new drop
     d\h%=meshhandle
     d\x#=drops_startx
     d\y#=drops_starty
     d\z#=drops_startz
     d\dropvelocity_Y# = 0
     d.onconveryor%=false
endif

function updatedrops()
  for d.drop=each drops
      if dropcollided then;(dosome kind of collision/pick to get this)
         animate d\drop ;possible splat anim
         d\onconveyor=true
         d\dropvelocityY=0
         rotateentity d\h,(direction of conveyor)
      else
         d\dropvelocity=d\dropvelocity_Y + gravity#;needs setting up to a suitable value, try 0.01
     endif  
     
     
     if d\onconveyor moveentity d\h,0,0,beltspeed

     translateentity d\h,0,-d\velocity_Y,0;move ent down by gravity regardless of orientation

     if dropnolongerneeded;ie off screen
         assasinate_drop(d.drop)
     endif

  next
end function

function assasinate_drop(d.drop)
   freeentity d\h
   delete d
endif