Shaykh Salih al-Fawzan said, when asked about the ruling on using beads for remembering Alllaah:

The tasbeeh beads (misbahah), when a person makes use of it, believing that in using it there is some excellence and virtue, and that it is from the ways and means of the remembrance of Allaah, the Mighty and Majestic, then this is an innovation. As for when a person uses them from the angle of the permitted things (mubaahaat), or that he counts those things with them which he needs to count, then this is from the permitted affairs. As for taking them as religion and nearness, then this is treated as [being from] the newly-introduced innovations.

And it is better that a person glorify (Allaah) and count the tasbih (glorification) by his fingers, this is what is desirablel. As for taking the beads upon the understanding that there is virtue in them as is believed by some of the Sufis and their followers and for which reason you find them carrying these bulky beads and wearing them around their necks, this enters into showing off (riyaa) from one angle, and it has no foundation in the Shariah (from another), hence making use of it and employing it becomes from the newly-introduced innovations. Nur alaa al-Darb Fatawa Shaykh Salih al-Fawzan (1/81) through al-Bida' wal-Muhdathaat (p. 343-344).