Of course. I hardly ever cast circles in my magical workings...but then I tend to invent most of my spells intuitively or base them loosley on pre-existing rituals, so you won't find them in books or the like.
Are you after a particular kind of spell? I can't be bothered to put up a list of my spells, so here's a few links to the spells I've provided to others on this forum in the past...none of which require the casting of circles.
http://www.everythingunderthemoon.net/f ... php?t=4127
oh and here's one I couldn't get the link to work for, so I'll just post the spell.
Spell to Ease Depression:
1: Create an altar if you don't already have one. The main feature is it must have a pentagram/pentacle on it. Wood is best. For mine I simply use a wooden box) Place it facing east (where the sun rises from for easy reference)
2: Place an incense cone inside the star. Place a white candle to the right of the pentagram and a quartz crystal to the left. Place a ring with any kind of natural stone set in it, (or if you don't have one a necklace will do as long as it has a natural stone) above the pentagram.
3: Kneel behind the altar (facing East) and light the incense and the candle.
4: Go to the bathroom and smear yourself with anything you like. Traditionally a raw egg is used and you wash it off in the river. But you can use anything (i used moisturiser ) This represents how you have been feeling in the past. Then turn on the taps of the bath or shower and recite before you step in (you can say it in Romani or in my English translation) :"Feri ando payi sisholpe te nauyas" (It was in the water that one learned to swim) and step into the shower, symbolically washing off the past (don't expect a miraculous change-it is really very gradual in reality, but things will change).
5: After you have washed yourself, return to the altar (dressed or undressed, it doesn't matter). Kneel before it once again, reciting:
"Feri ando payi sisholpe te nauyas.
May angle sar te merel kadi yag,
Ankana mukavv tut le Develsa.
Ando gav bi zhuklesko jal o pavor i destesk.
Chailo sim"
(It was in the water that one learned to swim,
before this fire burns out,
may you rest with all the Gods (though you might prefer to say Ashes to ashes, dust to dust, rather than a literal translation)
In the village without dogs,
The farmers walked without sticks,
I am fulfilled.)
Then write on a piece of brown paper your wishes, simplified. e.g: I am strong. I am filled with the joy of the universe. I am in control of my life. (write as though it has already happened -this is important!!.
Burn the paper in the candle flame and take these ashes as well as the ash from the incense. You can do what you like with them. I put them inside a copper elephant. You might like to bury them uner your favourite tree or throw them into a stream. Then put on the ring or hang it on a chain or put on the necklace. Whenever you look at the ring ot\r necklace, remember the spell.