Shimmering Grotto

Great Card.
Its drawbacks are not bad when you look at the card as a whole.
Using a land slot helps free up some room and put more awesomeness in my deck.
It also can produce ANY color land... Try doing that for less than .25cents(cost of card at the time)
AND
It backs itself up with being able to tap for a colorless mana.
The bleed of one land to use it does slow me down but multi color spells are usually cheap casting cost and powerful anyway.
If the bleed is too much for you and your bank account isnt the federal reserve, i would consider Rupture Spire.

Definitely a solid mana-fixer -- think of it as the poor man's City of Brass. Probably best for a casual, non-competitive player (like myself).

Tired of pain lands, ouch, can't afford the old classic dual lands? This may be one of the best mana fixing cards for multi-color decks that has come out. Make that hard to work card with three or more mana color costs to activate work a little more easily for yourself.

Works well in 5 colour decks, but not much else. Also renders 'School of the Unseen' useless.

Even in non-competitive, this card's crap, use the artifact from time spiral that does the same thing, that way you are not wasting a land slot. this is soooooo slow. When I see people play it, they almost always wish they had something better, the land type they need instead of something that drains your mana away.