The phrase "slipping along" can be replaced by a variety of synonyms to convey a similar meaning. One option is "gliding," which suggests a smooth, effortless movement. Another possibility is "skimming," which implies a light, rapid motion. "Scooting" is also a suitable replacement, indicating a quick, nimble movement. "Sliding" can also be used as a synonym, although it may suggest a slower, more deliberate pace than "slipping along." Other alternatives include "coasting," "cruising," and "glancing," each of which conveys a sense of effortless motion. Ultimately, the choice of synonym will depend on the intended context and tone of the writing, as well as the writer's personal style.